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Developing allergies in school is commonly seen in young infant and children who start spending more time away from home. Frequent health ailments such as repeated coughing, watery nasal discharge, skin rashes and tummy troubles can occur following school attendance. In some, the child can even be cranky, crying, refusing to go to school due to the uncomfortable symptoms. These can be tell-tale signs of allergies.
This article is written to improve awareness of potential allergies that children can be exposed in school. Early detection of allergies in children helps to improve the child's quality of life, minimizing absenteeism from school and prevent disruption of daily learning school experience.
Atopic diseases are constellation of medical conditions that can affect various organs including the respiratory system, the skin, and the gut. Atopic diseases are complex immune conditions that remain partially understood medically. In atopy, there is a genetic predisposition of susceptible person to develop allergy. This is further triggered by afterbirth environmental stressors- such as infection, irritants, surrounding allergens/ proteins and etc.
The immune system of an atopic person is able to mount an immense inflammatory exaggerated response when it is exposed to a usually harmless protein/ allergen in the environment, resulting in allergic symptoms clinically. Atopy in early infants and children is also explained by the 'hygiene hypothesis' whereby due to 'more hygienic environment' and less exposure to 'allergen/ trigger-proteins', the child is more predisposed in developing atopic diseases.
Childhood atopic conditions include atopic dermatitis, food allergy, allergy rhinitis and allergic asthma. In those children with atopic conditions, they are at risk of developing another atopic condition during their childhood, a common term known as 'atopic march'. This is due to the association and interlinkage of these atopic conditions. 3 out of 4 children with atopic dermatitis will develop allergic rhinitis, and 1 out of 2 with atopic dermatitis will develop asthma.
Atopic dermatitis (also known as eczema) is one of the most common recurring non-infectious, inflammatory skin condition presenting in the early childhood. One suffers from recurring flaky, dry, red, itchy, oozy, crusted skin rash. The rash can affect any part of the body. Atopic dermatitis is frequently associated with allergies due to genetic innate skin barrier dysfunction and further triggers from environmental factors such as stress, irritants, infections, heat, humidity and allergens. 1 in 4 children with atopic dermatitis have concurrent food allergies.
The relapsing and chronicity of skin inflammation can take a toll on a child's growth development resulting in poor sleep quality, psychosocial impact in school (due to skin physical appearance), reduced quality of life, and increases risk of skin infection complications.
This is the most common childhood diseases due to allergies. It is also known as 'hay fever'. Affected children presents with upper airway symptoms such as nose congestion, watery nose, sneezing, post-nasal coughing, frequent mouth breathing, itchy and watery red eyes, even ear infections.
When allergic rhinitis is not managed, it can affect a person's breathing, resulting in poor sleep quality, constant mouth-breathing and poorer growth of the teeth and facial bone structures. Recurring upper airway infection such as sinusitis, ear infection can result in hearing impairment and poor speech development. In some cases, allergic rhinitis may progress to allergic asthma as part of the atopic march - as a progression of the allergy disease.
A person with food allergy can experience allergic symptoms such as rashes, lip swelling, eye swelling, breathing difficulty or even anaphylaxis. Presentation of food allergies in children can be much subtler with symptoms such as poor feeding, refusal of food, abdominal cramps, diarrhea, vomiting and failure to thrive. It is important for parents and physicians to pick up food allergies in children as their symptoms can differ compare to adults and their symptoms are commonly mistaken as a stomach infection/ flu.
Undiagnosed food allergies can lead to prolonged poor gut absorption, malnutrition, failure to grow, and stunted childhood development.
Sensitization of airborne allergens and food protein allergens can contribute to allergic asthma in children. Symptoms of allergic asthma is often described as persistent cough, wheezing (musical sound) when breathing, shallow/quick and labored breathing. Those with other forms of atopic diseases such as food allergies, atopic dermatitis and rhinitis have increased risk of developing allergic asthma- as part of the atopic march progress.
Chronic allergic asthma can be associated with poorer quality of life of the child, frequent school absentees due to asthma attack episodes and weaker school performance, weaker lung function and more side effects from asthma long-term medications.
Children who have started schooling can be exposed to various environmental allergies. As school is the main channel to cultivate and nurture a child's learning, children are encouraged to interact with people (teachers, schoolmates), various activities and both indoor and outdoor surroundings. During this journey, one may be inadvertently in contact with allergens in the school environment.
Common allergens that can be found in school compounds- both indoor and outdoors include
School meals from canteen/ sharing of food with other classmates can potentially expose susceptible children to food allergies.
Common food allergens that can trigger allergy include
Allergies in school may not develop immediately. The allergen can be introduced into the body of the child through inhalation, direct skin contact or oral consumption. Over time, the immune cells in the body are sensitized and able to recognize the allergen, leading to a cascade of inflammatory immune response that can be clinically seen as allergic/ atopic symptoms.
School environment can be a reservoir for various pathogens (bacteria, viruses, fungus) to thrive. Children who attend school can be exposed to these environmental microbes. Atopic children who acquire infections from school can have flare-ups of their atopic diseases due to triggering of underlying immune system following an infection.
On the skin, common bacterial infections such as staphylococcus bacteria infection, or viruses such as molluscum contagiosum and herpes viral infection can trigger a flare up of atopic dermatitis in susceptible children
As for respiratory symptoms, children that are exposed to common airborne viruses such as Influenza A/B, Covid virus, Adenovirus, RSV (Respiratory Syncytial Virus) can result in persistent respiratory allergies such as allergic rhinitis/ allergic asthma.
As young children or pediatric groups are less vocal and less able to describe their symptoms to the adult, as family member, school teachers or physicians, it is imperative to recognize the symptoms that the child is not well.
A child with allergy may present with subtle, non-specific signs such as cranky, crying, poor appetite, refusal/ withdrawal from engaging in school/ certain activities.
Other common symptoms include:
| Areas | Symptoms |
| Skin | Hives, eczema rashes |
| Lungs | Cough
Wheezing (musical sounds when breathing) Shortness of breath Labour breathing |
| Eyes/ Nose | Runny nose
Sneezing Itchy and watery eyes |
| Gut | Diarhoea, vomiting
Abdominal pain |
Symptoms of anaphylaxis should not be missed by any adults. The catastrophic allergic symptoms are characterized by acute unwell of a child, labored and difficult breathing, wheezing, choking, facial puffiness, eye, lip, tongue swelling, generalized hives and rashes over the body. In those situation, do immediately bring your child to the emergency department as this can be life threatening.
If you have concern of allergies that your child may have developed following attending school, do reach out to your healthcare providers for further evaluation.
Your doctor will usually evaluate your child's concern and symptoms, determine a correlation of your child's symptoms and certain triggers that can be found in school. In school allergies, your child may notice his/ her symptoms are better or resolved when he/ she is away from school, and symptoms may recur or worsen on school days.
In real world, symptoms association may be vaguer with potentially other confounding factors. In such cases, allergy tests can be beneficial in teasing out the underlying allergies.
Most allergy tests for school allergens can be done safely in outpatient settings under the guidance of your healthcare provider.
Worth speaking to your doctor on which are the suitable tests for your child to understand any underlying allergies.
If you suspect your child has school-related allergies or needs a personalised action plan, don't wait to seek expert help. Our doctors specialise in accurate allergy testing and creating effective management strategies for children. Schedule a consultation today to ensure your child's safety and well-being.
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Outdoor allergies are becoming increasingly common in Singapore. The concept 'urban green' is no longer foreign to us living in sky-scraper city like Singapore. Public gardens, lakesides, parks, even in-build lush verdant greeneries in private condominium and apartments are made for long term environmental sustainability with better air quality and healthier ecosystem in the midst of urban living.
With that, outdoor activities such as jogging, running, cycling, walking our pets become one of the most cost effective, healthy, popular activities in Singapore. These subject one towards outdoor particles and allergens, potentially resulting in development of outdoor allergies overtime. The prevalence of respiratory allergy symptoms such as allergic rhinitis and allergic asthma is rising with urbanization.
In this articles, we discuss about common types of outdoor allergies, symptoms-associated and how we can manage these inevitable allergies in our lives.
Outdoor allergies that are commonly seen include:
As Singapore does not have climate with 4 seasons, we do not experience seasonal or perennial pollen exposure. Locally, we are commonly exposed to grass and weed pollen. Having said that, due to the diversity and metropolitan aspect of our country, good local and global infrastructure, frequent travelers in and out of the country may bring along pollen with them from overseas.
Efforts of promoting greens, combating global warming, healthy living, motivating exercise, result in parks, park connectors, lake gardens budding around Singapore. Most of the newer condominiums in Singapore also has their own greens and landscape. These can potentially expose one to airborne pollen allergies.
The immensely high humidity in Singapore is a perfect breeding ground for mold and fungi both indoor and outdoor as well. One can be repeatedly breathed and exposed to mold and fungi spores in their surroundings, resulting development of allergic symptoms.
Although dust mites are more commonly seen as an indoor allergen, due to the hot and humid weather of Singapore, densely populated geographical size, dust mites can also be found outdoor. This inhalant allergen is one of the most common allergens in Singapore responsible for various respiratory and skin allergy symptoms.
Over the years, Singapore is promoting a culture that is pet-friendly, encouraging pet adoptions and ownership via awareness campaign, supporting pet industry and etc. Pet population in Singapore is on the rise with people keeping more dogs and cats. As a result, cat and dog dander (or even other animals such as hamster/rabbit etc) can be found in the air, linen, environment around us. Even if we do not own a pet, we may be exposed to pet dander when we are outdoor. Pet dander is known to be a potential allergen associated with allergy symptoms such as chronic rhinitis, asthma or even eczema.
We can be exposed to mosquitos, insects, bees, hornet, wasp, fire ants when we are outdoor in the garden or park. Insect venom or foreign body is firstly introduced into a person's body over the bitten/sting site, resulting in the body's immune system to react and mount an inflammatory allergic response.
Insect bites or stings can trigger allergy reactions ranging from mild localized allergy pain, swelling and itch over the affected area, to possible full blown life-threatening anaphylaxis symptoms.
Outdoor allergies can affect any susceptible individuals including children, adults or even elderly. It can affect our quality of life due to persistent allergy symptoms leading to disruption of our daily routine, poorer quality of sleep, chronic fatigue, low mood, abysmal work performance, and weakening social interactions with others. Untreated outdoor allergies can incur an economic burden due to repeated medical visits/ treatment, absentees from work and school.
One may experience prominent allergic symptoms while outdoor and symptoms may be resolved following returning home/ going indoor.
Common outdoor symptoms may affect various organs of the body as summarized below:
| Body Organs | Allergic Symptoms |
| Eyes and Upper Airways | Snuffly, watery, blocked nose
Sneezing Itchy, watery, puffy eyes Throat itching Lip swelling |
| Lungs | Coughing
Shortness of breath Chest tightness Wheezing |
| Skin | Itching
Hives Eczema |
| Generalized (Anaphylaxis) | Facial swelling
Eyes and Lips swelling Airway tightening Difficulty breathing Whole body hives rashes Fainty |
In the event of anaphylaxis, one should immediately call for help/ ambulance and get assistance to go to the hospital for allergy treatment without delay as one can succumb to anaphylaxis and it is a reversible severe allergic medication emergency.
Outdoor allergy symptoms may not be so clear-cut in real life, as one may concurrently suffer from other allergens found in our living environment- including indoor allergies. Hence, in real life, sometimes allergy symptoms may not improve even when one no longer remains outdoor.
A clear history of associated worsening allergic symptoms when being outdoor is key in diagnosing outdoor allergies.
One may notice certain 'season' , ' pattern' or ' particular activities' that can be associated with more pronounced symptoms. Symptoms of concern may abate following going indoor.
When diagnosis is uncertain, allergy tests can be offered to confirm or rule out the allergy.
Many of outdoor allergens can be tested with
or
If you have concern of suffering from outdoor allergies, you should consider speaking to your healthcare providers for further evaluation of your symptoms.
If your allergy symptoms are persistent, your healthcare providers may prescribe
Allergen-specific immunotherapy is available for pollen/ grass allergies, mold/ fungi allergies, dust mites and animal dander allergies. These are individually made immunotherapy effective in re-education and modulation of one's immune system against specific allergens, progressively diminishing the allergic inflammatory response, leading to reduction and remission of allergic symptoms. Immunotherapy is available in the form of sublingual (under the tongue) tablets or sprays. Do speak to your doctor to find out more.
Take control of your outdoor allergy symptoms with expert guidance tailored to your needs. Our team is here to help you manage triggers and breathe easier every day. Reach out to us today!
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From fear factor to finer dining, edible insects have been gaining headlines and popularity in recent years. Edible insects are proven to be beneficial to our health, packed with proteins, micro-minerals and unsaturated fats. In the olden days, medieval Rome and ancient Chinese had incorporated insects into their diet.
The other perk of shifting our human palate towards edible insects is for a better greenhouse effect and long-term sustainable food supply chain. Growing insects in farms requires less energy, water and space in comparison to farming poultry. The waste of the insects can be recycled and used as fertiliser to fruits and vegetables.
Amidst making headlines, arousing curiosity in many on this superfood, we also want to explore the safety and association of edible insects with allergic reactions.
Currently the Singapore Health Authority has approved 16 species of insects as edible food.
Insects that can be consumed include crickets, super worm, grasshopper, locust, mealworm, moth, silkworm, honey bee, beetle grub and white grub.
Insects can appear gross and gruesome, but they can be a food source for various good nutrients. Edible insects are rich in proteins, good fatty acids such as omega-3, vitamin B12, riboflavin, iron, zinc, antioxidants, and fiber. Furthermore, the protein chitin that can be found on the skeleton of the insects when consumed has anti-microbial properties. Edible insects also have anti-inflammatory properties, reducing our long term cardiovascular risk factors by regulating our cholesterol and blood sugar.
In a global health perspective, by opting for edible insects, we can ensure better usage of worldwide resources in farming when compared to conventional livestock, resulting in a more durable food supply chain in long run.
Those with known shellfish allergy can experience allergic reaction when consuming insects due to the cross-reactive proteins between insects and crustaceans. For example, one with known shrimp or crab allergy may develop allergic reaction when consuming insects.
The common insect allergens are proteins such as tropomyosin, arginine kinase. These proteins play important roles in contracting the muscle and regulating metabolism of the insects. These similar proteins can also be found in shellfish such as crustaceans and mollusks, parasites or even worms. To add things further tropomyosin can also be present in cockroaches and dustmites. Hence, one can have cross-reactivity between shellfish-dustmite-cockroach-edible insect allergies.
For allergy to occur, one has to be exposed to the allergen for the first time (primary sensitisation), allowing the immune system to recognise and remember the allergen. When the person is exposure again to the allergen for the subsequent time (secondary sensitisation), the body has a recollection and mount an exaggerated immune inflammatory response against the allergen.
In the case of edible insect allergy,
One may ask, if we heat up/ cooked/ boiled the insects, can we prevent allergic reaction when consuming them? Similar to shellfish allergy, due to the stability of the allergenic protein towards heat, processing insects are unlikely to break down the proteins and prevent allergy. You can still develop an allergic reaction consuming cooked insects.
Those with known edible insect allergies, past shellfish allergies, known dustmite or cockroach allergies.
Edible insect can trigger allergy and present itself with various symptoms. It is important to recognise the symptoms and seek medical attention without delay.
Our body’s various organs can react to insect allergy as below:
| Body System | Allergy Symptoms |
| Face/Mouth Region | Swelling of the face, eyes, lips, tongue, throatWatery eyes |
| Respiratory | Watery noseCoughBreathing difficultyShortness of breathWheezing |
| Gastrointestinal | Nausea and vomitingDiarrhoeaAbdominal painBloatedness |
| Dermatological | Itching of skinHivesEczema |
Severe reaction that we should not neglect: Anaphylaxis: an acute sudden severe, dangerous allergic reaction developed over seconds to minutes with systemic symptoms such as dizziness, faint, unable to breath, generalised rash, closing of airway, generalized rash. You will need immediate medical emergency otherwise one can succumb to the allergy.
Less common in comparison to allergy, histamine poisoning following eating insects can occur due to a release of histamine from insects following cooking and prolonged storage. Having a large amount of histamine in our body can result in acute symptoms such as generalised rash, difficulty breathing or even anaphylaxis and will require immediate medical attention as this can be life threatening.
Your healthcare provider can assist you in the diagnosis of insect allergy.
A proper history with clear cut association of allergy symptoms following consumption of insects is important to nail down the allergic diagnosis.
Allergy tests in the form of RAST IgE blood test or skin prick tests against shellfish, dust mites and cockroach particles can facilitate one to understand whether they are likely to be allergic to edible insects due to the cross-reactivity between the allergens. You should not hesitate to reach out to your healthcare provider to discuss on which tests which are suitable in your condition.
Curious about whether edible insects might trigger an allergic reaction for you? At Dr Ben Medical Clinic, we can assess your allergy risk and guide you on safe dietary choices. Book a consultation today to get personalised advice based on your health profile. Contact us here.
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Consuming wheat has commonly been highlighted in social media and news that it can badly impact the body resulting in weight gain, vomiting, unwell, poor brain function. In this article we would like to highlight on the positive nutritional aspect of eating wheat and increase awareness on some of the negative health conditions associated with wheat that can be seen in susceptible individuals.
Wheat has been our main staple diet for more than 10000 years. The wheat proteins are packed with amino acids that helps the body generating cells and metabolism. It provides us fiber, macro- and micro-nutrients and serves as energy fuel for our daily life. Wheat grains have various vitamins including vitamin B complex, vitamin E, folic acid, phenolic acid antioxidants and also have minerals such as calcium, phosphate, potassium, magnesium, zinc, iron, selenium, copper and etc.
The wheat comprises of an outer layer of bran and germ, and an inner core full of flours.
Wheat grains are free of cholesterol, has low sugar, fat, sodium, saturated fatty acid and suitable for maintaining a good cardiovascular profile. Most of the healthy nutrients are concentrated on the outer layer, hence full grain is encouraged in modern healthy diet.
Over the years, there are increasing prevalence of wheat-related disorders reported. This is mostly due to adverse reactions following consumption of wheat resulting in an immune inflammatory response in affected individuals. Wheat-related disorders are an umbrella group of medical conditions secondary to wheat hypersensitivities including celiac disease, wheat food allergy, wheat-dependent exercise- induced anaphylaxis, irritable bowel syndrome and etc.
Celiac disease is a lifelong autoimmune condition of abnormal absorption of the small intestine triggered by consumption of gluten in susceptible persons. The symptoms of celiac disease can be triggered by gluten that is found in wheat, rye or barley.
Those who are genetically susceptible to celiac disease experience failure to thrive following consumption of gluten. This is resultant of gut malabsorption of the main micronutrients from the diet. Young children and adolescent may even have difficulty in putting on weight or delayed puberty.
Other common symptoms are summarised here:
| Symptoms | |
| Gastrointestinal System | BloatednessIndigestionDiarrheaAbdominal painNausea and vomitingOily stool (difficult to flush) |
| General System | Lethargy/ Low energy levelDizzinessNight blindnessSkin rashAnemic/PaleBrittle bonesLow body mass index |
Wheat is a common food allergy following milk and egg allergy. Wheat allergy occurs following
The allergic symptoms of wheat allergy can be confusing as it may present as very mild and non-specific overlapping with common gastro-intestinal disorders.
| Areas | Allergic Symptoms of Wheat |
| Respiratory System | Snuffly, watery nose and eyesShortness of breathThroat constrictingBreathing difficultyCoughWheezing/ Asthma |
| Gastro-intestinal System | BloatednessIndigestionNausea and vomitingDiarrhea |
| Dermatological Area | Itchy SkinHives, Eczema rashFacial swellingLip/Eye swelling or rash |
Rarely, in a catastrophic allergic reaction, one may develop anaphylaxis following exposure to wheat, leading to seconds to minutes of severe allergic reactions such as facial swelling, airway constriction, breathing difficulty, circulatory collapse with drop in blood pressure. One can feel extremely unwell, experiencing fainting spell, unable to breath, rash, and will require immediate medical allergy treatment as this can result in death if left unattended.
This type of wheat allergy is an occupation-related allergy seen in those who have contact with wheat such as bakers, millers, flour handlers or confectioners. Exposure to wheat allergen protein can occur through inhalation or direct skin contact of wheat particle during work. Wheat proteins such as flour, rye, barley oats can trigger such allergy.
Following repeated exposure to these allergens, the immune system recognizes the wheat allergens and start to mount an allergic response. The symptoms tend to become worse overtime with repeated exposure as this increases the sensitization against the allergen over time. One can present with breathing difficulties, repeated cough, and asthma.
This is a rare form of wheat allergy where one does not have allergy reaction from consuming wheat on its own. However, severe disastrous allergic reaction can be triggered by provoking factors such as exercise, medications (NSAIDS, Aspirin), alcohol or even stress when concurrently taking wheat. While the underlying cause remains unknown, it is postulated that these triggering causes increase gut absorption of wheat protein allergens into the blood circulation resulting in immune allergic response.
One who is experiencing WDEIA can present with a wide range of symptoms from mild hives, facial and lip swelling to even severe symptoms of anaphylaxis.
Irritable Bowel Syndrome (IBS) is a functional gastrointestinal condition affecting 5-20% of adults. It is a diagnosis of exclusion with non-specific gastro symptoms such as flatulence, bloatedness, abdominal pain, discomfort, diarrhea, constipation, lactose intolerance and etc. IBS symptoms can be aggravated by certain food such as wheat or carbohydrates.
The underlying cause of IBS is poorly understood. It is considered a ‘functional’ diagnosis as patients tend to undergo a battery of investigation tests that come back as normal. Research over the years postulated that there is a psychosocial element in the cause of IBS where there is communication of the brain-gut axis, changes in the gut microbiome, increase in permeability of the intestinal linings which result in its effect on the gut immune system and IBS symptoms.
If you are suspecting of experiencing adverse symptoms following consumption or exposure to wheat, you are advised to discuss with your healthcare provider on this matter.
A good succinct history with reproducible symptoms repeatedly following exposure to wheat is vital in diagnosing wheat-related disorders. In cases that are more ambiguous, one can consider
to delineate the causes of wheat-related health symptoms.
Baseline micro-nutritional blood tests may be considered to understand the extend of nutritional deficiency in the wake of long term wheat-related symptoms.
Whether you’re exploring the health benefits of wheat or suspect you may have an allergy, professional guidance can make all the difference. Dr Ben Medical Clinic offers comprehensive evaluations to help you find clarity and confidence in your food choices. Book your consultation with us and take charge of your health.
References:
Atopic allergy diseases can occur as a result of an exaggerated immune response by the body following exposure to a trigger allergen. It can manifest itself in the form of atopic respiratory conditions such as allergic rhinitis and allergy asthma, skin conditions such as atopic dermatitis and even the gut as food allergies. Conventional management of atopic disease involves avoidance of the trigger allergens, optimization of symptomatic medications such as antihistamines and steroids.
We cannot deny the evidence of genetic predisposition in some towards allergy. However, there are increasing medical evidence to suggest epigenetic factors such as our nutritional status of the body can overtime contribute to a person’s predisposition of developing allergy.
In this article, we highlight the connection between micronutrient deficiency and development of allergy. The understanding of the link between the two can have an impact to the current management of allergic conditions.
Iron is an element that can be found on earth ubiquitously. It is found in most living things that requires oxygen. It helps in the respiration of cells and has a role in the general immune system.
Our body contains 4-5g of iron. Two third of the iron is stored in a part of red blood cells known as heme (hence red cell is known as hemoglobin). A large amount of iron is also kept in the liver and a type of white cells known as the macrophages. Lesser, iron is also kept in the muscle proteins known as myoglobulins.
In our body, the iron usually presents as ferrous (Fe2+) or ferric (Fe3+) state. In environment that is rich in oxygen, free iron tends to be in ferric (Fe3+) state, while in environment lack of oxygen, iron tends to be in ferrous state(Fe2+). Iron is usually bound to protein- such as in the case of hemoglobin, transferrin etc.
Although on average we consume 10-20mg of iron from our diet only 1-2 mg is being absorbed daily. The iron is absorbed in the small intestines (the duodenum and jejunum).
A third of the people in the world has iron deficiency. Iron deficiency is more predominant in female, blood donors, vegetarians and growing infants. The World Health Organization (WHO) defined anemia as hemoglobin levels <12g/dL in female and <13g/dL in men. However, hemoglobin level can vary due to ethnicity or even if one is living in high altitude.
Logically, there are two common causes of iron deficiency- either we lose the iron through bleeding such as menstrual cycle, or we do not receive adequate iron from our diet in the case of vegetarians etc.
Interestingly, there is a third reason for iron deficiency- functional iron deficiency. In functional iron deficiency, there is immune response activation, leading to ‘immobilization’ or ‘underutilization’ of the iron in the body. To make things worse, there is reduced ability of absorption of iron from the diet during immune inflammatory response. Functional iron deficiency can occur as a result from chronic medical conditions such as infection, heart failure, allergy, chronic kidney disease, autoimmune or even obesity.
While we know allergies or atopy conditions tend to be genetically predisposition, environmental factor such as micronutrient status can contribute to allergy as well.
It is known that those who are pregnant with iron deficiency increases chance of having infants with allergy. Intriguingly, one with allergy is also more at risk of having anemia. Children with atopy such as eczema, asthma, allergic rhinitis, food allergy have higher association with anemia. Expectedly, avoidance of development of allergy can occur in those with improvement of iron levels.
Furthermore, micronutrients such as vitamin D, folic acid, vitamin A, zinc also have a role in our genetic makeup and immune system surveillance.
In those with deficiency in micronutrients, the immune cells in the body can be in a constant ‘heighten-alertness’ state. Lack of these minerals are associated with increased inflammatory response when encountering allergen, resulting in exaggerated immune response when the body encounters allergens or triggering proteins.
Macrophage - a type of white cells found in all tissues and blood circulation –serve as the soldier of our body to monitor and guard against pathogens. At rest and baseline, macrophage also help to store iron minerals in the body. In the state of persistent iron deficiency, there is a shift of the function of macrophages (rather than storing iron) to pro-inflammatory state, leading chronic low grade inflammatory response in the body and at risk of developing allergy.
In addition, when one is deprived of sufficient iron in the body, mast cells- an immune cell which has a significant role in allergy and infection- also become unstable. The mast cells contain small pockets of proteins known as histamine granules. When they are unstable, the granules are ‘ready to burst’, releasing histamine that contributes to inflammation and allergy.
In summary, iron deficiency can have a pro-inflammatory effect to the immune cells, leading to disequilibrium function of immune cells, producing exaggerated inflammatory response and allergy symptoms.
Yes, micromineral levels such as iron, vitamin D, zinc, folic acid levels can be safely tested through blood tests.
Having a daily healthy and balance diet is key in receiving sufficient nutrient for the body.
A variety of diet rich in micronutrients such as red meat, fish, innards, chocolate, legumes, cereals, fruits, fortified milk, whey protein, fruits, vegetable, legumes can be beneficial in reducing risk of developing allergy.
Perinatal healthy nutrients rich in iron, zinc, vitamin A, D, vitamin C are vital in determining the health of future offspring and reducing the risk of developing allergy, thereafter avoiding atopic march in the future offspring.
In the case of insufficiency of micronutrients from our daily diet, oral supplement can be used to boost the levels of micronutrients in our body.
Improving the micronutrient levels in the circulation can result in a more stable and resilient immune system, preventing chronic inflammation and allergy.
Boosting and compensating micronutrient deficient level in pregnant mother and infants has shown to improve overall immune cell inflammatory response, reducing risk of atopy in infants and potentially halting the progress of atopic march in later life.
Fascinatingly, intervening and targeting micronutrient deficiency can be considered as an ‘allergen-independent’ way of stabilizing the immune response, alleviating and controlling atopy symptoms.
If you're experiencing persistent allergy symptoms, a deeper look into your micronutrient levels could offer valuable insights. Schedule a consultation with Dr. Ben Medical Clinic to explore a personalised allergy treatment in Singapore.
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Allergies in our workplace can occur insidiously and post a significant cause of concern to our health. It is imperative to pick up and identify occupation allergies early to reverse and alleviate the allergic symptoms. Prolonged exposure to occupational related allergens may lead to detrimental health complications and possible irreversibility of the symptoms despite withdrawal from the offending trigger.
In this article, we would like to highlight the subtle yet potential allergens that we may have encountered in our daily workplace.
Allergy is a medical condition that occurs following an exaggerated immune response towards an external harmless substance. An allergen is a substance that is harmless but able to trigger the immune response, resulting in an allergic reaction.
One can be exposed to the allergen by inhaling it through the nose, upper airway, then into the lungs, or through direct skin contact or even via oral consumption into the gut. Once the body is exposed to the allergen, immune cells in our body can recognise and produce an inflammatory response against these substances. With repeated process of exposure and recognition of the allergen, the body becomes 'sensitised' and mount a quick yet abnormal response whenever it encounters the same allergen.
Clinically, this manifests as allergy symptoms. If the symptoms occur on the skin, one may experience itchy eczematous rashes or in the form of contact dermatitis. When the symptoms affect the respiratory system, one may present with asthma or allergic rhinitis symptoms.
Workplace asthma can be induced over time by air particles that are inhaled during work, eventually causing persistent cough, wheezing and shortness of breath. The symptoms that are related to workplace can be insidious and slow, and occur after years of working in the same environment. This is due to progressive sensitisation when a person is chronically exposed to the airborne chemicals and allergens in the workplace.
Some of the common airborne allergens associated with allergic asthma and the association with certain jobs are highlighted below:
| Job Nature | Airborne allergens |
| Hairdresser | Hair perming agents such as persulphates |
| Baker | Wheat flour, amylase enzyme |
| Builders | Sawdust, wood dust |
| Solder technician | Solder fumes |
| Factory workers | Colophony, epoxy resin, plastics, glues |
| Storehouse keeper | Dustmites, Mold |
Furthermore, airborne irritants such as dust, fumes, and chlorine can irk the respiratory system and trigger asthma symptoms as well.
Sensitivity to the airborne allergen increases over a time period upon repeated exposure at work workplace. Once sensitisation occurs, the affected person can develop asthmatic symptoms even with a mild/ small amount of exposure to the allergen. Allergic asthma symptoms tend to improve when one is on leave, away from the affected workplace, or better during the weekends.
If you notice you have a tendency to sneeze, have excessive nasal secretion, blocked nose, cough, when you are at work, there is a possibility this can be occupational-related. One tends to develop symptoms of allergic rhinitis secondary to the workplace following repeated and chronic exposure of the triggering allergens in the same environment.
This is commonly seen in dust mite allergies leading to chronic unresolved allergic rhinitis symptoms in dusty working environment. Allergens such as wheat, flour, yeast can trigger allergic rhinitis symptoms in bakers who inevitably inhale in these allergens during the preparation of dough. Irritants such as coal dust, chlorine, and talc can also trigger allergic rhinitis symptoms.
It is worth noting that often allergic rhinitis precedes the progression of allergic asthma. Being able to pick up, manage allergic rhinitis and identify the triggering allergen early are vital in preventing the progression of allergic asthma.
The most common occupational-related allergy condition is related to allergic skin diseases, such as contact dermatitis. It is also one of the main causes a person takes time-off or unable to complete his work.
Due to direct skin contact to the allergen that is found at the workplace environment, the immune system can be sensitised and manifest itself with skin eczematous rashes that is worse when one is at work, and improve when one is away from work and away from the offending allergen. Skin allergic symptoms can be a nuisance, resulting in incessant itch, broken skin, pain, and affects negatively a person’s quality of life and work performance.
Some of the common occupation and allergens that can cause allergic contact dermatitis are summarized here:
| Job Nature | Contact Dermatitis Allergens |
| Healthcare workers such as nurses/dentist | Latex found in gloves, medical instruments, surgical equipment |
| Hairdressers | Paraphenylenediamine (PPD) found in hair dyes |
| Printers | Acrylic dyes, adhesive tapes |
| Florists | Flowers such as Ivy, ilies |
| Mechanics | Benzene |
| Scuba diver | Latex found in scuba diving/ elastic suits |
| Food handlers | Latex found in gloves, Nickel allergies, certain food proteins |
You may be surprised that one can still have allergy issues in an average office indoor environment.
Due to prolonged air-conditioned indoor environment, poor proper air ventilation, minimal sunlight penetration, and lack of proper maintenance of the ventilation circulation, one can be exposed to airborne allergens such as dust mites, mold, cockroach particles and etc. Less commonly, one may even experience contact dermatitis over their fingers, arms due to direct contact to cleaning agents that are used to wipe desk surfaces.
You may wish to discuss with your doctor on your job nature and environment for your health care professional to tease out further any potential allergens.
If you suspect of having occupational allergy, you can consider discussing your symptoms with your health care professionals.
Your doctor would want to understand further on your symptoms and correlation with your work. History on your job nature, working environment will be useful. Your doctor will also want to understand whether your condition is better over the weekend or when you are away from your work.
In circumstances that there is concern of allergy to substances from workplace, your doctor may offer allergy test in the form of blood RAST test, skin prick test, patch test to evaluate further.
You can also inform your work place supervisor/ management of your health conditions if you have concerned about occupational related allergies.
The key management of occupational allergies is to avoid the triggering allergen and minimise exposure to the responsible allergen. However, this can be easier said than done due to the difficulty one may encounter to switch jobs without impacting socio-economically such as loss of income or even loss of employment.
Noticing allergy symptoms that get worse at work? Your job environment could be a contributing factor. Book a personalised consultation at Dr Ben Medical to better understand your triggers and how to manage them.
References:
The type of diet that one consumes regularly can play a role in the pattern differences in the type of food allergies seen across different parts of the world. In the western world, allergy to egg, cow’s milk, peanut is common. Although these food allergies occur in Singapore as well, the cases are relatively low. Nonetheless, there is a slight increasing trend of peanut allergy cases rising over the past decade, and it remains one of the most common causes of anaphylaxis in children locally.
In Southeast Asia, shellfish allergy is common as consumption is generally high locally. While fish is consumed regularly and commonly in Singapore,an allergy to fish is uncommon. Interestingly, there are certain food allergens that are unique and only seen in Asian population this include food allergies against bird’s nest, royal jelly, buckwheat, chickpeas, and chestnuts.
Food allergy in paediatric group is explained by ‘dual allergen exposure’ hypothesis. This theory suggests that a person’s immune response towards food proteins can differ depending on the first site of exposure during the first year of life. In children with atopic dermatitis, due to an impaired and leaky skin barrier, one may be exposed and sensitised towards food proteins when the impaired skin is in contact with the proteins.
Without intestinal tolerance, one can develop sensitisation and food allergy. Hence, even avoiding consumption of food allergens, one with atopy may still develop food allergy through ‘skin exposure’. On the other hand, if the child is introduced early of food protein through gut absorption, gut immune tolerance may occur, and this may prevent skin sensitisation towards the particular food.
Currently, the European Academy of Allergy and Clinical Immunology (EAACI) advises the introduction of various foods, including allergenic foods, after the age of 4 months to all children regardless of their history of atopy.
While food allergy is more commonly heard in the paediatric population, older people can develop food allergy as well. The diagnosis of food allergies in the older group tends to be a challenge due to other confounding medical illness as one progresses with age. The occurrence of food allergy in adult is associated with immunosenescence- the ‘aging of immune system’.
While elderly person may have oral food tolerance against allergies in younger days, food allergies can still occur in mid or later part of life. Over time, there is deterioration of general immune system with a shift of the body towards pro-inflammation. Furthermore, the gut becomes ‘leaky’ and more permeable as one ages allowing food protein/allergens to pass through the gut barrier into the body easily. Also, with age, the digestive ability may decrease, leading to more undigested protein in the gut that can potentially become an allergen.
Repeated insult to the intestinal lining with infections, unhealthy diet, medications, alcohol, smoking can have a long term impact to the gut microbiome, increasing risk of food allergy. Lack of certain micronutrients such as vitamin D, zinc, iron can be associated with pro-inflammation of the immune system, increases sensitization against food particles in older person.
The concern about the topic on ‘food allergy’ is one may wish to prevent ‘allergy’ by omitting out the common food that can cause allergies. A lot of time, the ‘idea about having allergy’ is either self-diagnosed, or childhood ‘hearsay’ without proper diagnosis or medical review, leading to unnecessary avoidance of ‘allergic food’. This can lead to long term nutrient deficiency, stunted growth/ development, or even ironically increase susceptibility of food allergies later in life (when one is exposed to the food allergens later in life).
If you have concern of food allergy, it may be prudent and beneficial to discuss with your health care provider or allergist on your symptoms.
Early exposure to a wide myriad of food proteins and antigens can help the immune system to become tolerant against the food proteins. Food protein may have anti-inflammatory effect and reducing immune reaction against allergens. When a person is consuming a wide variety of diet, one will have a wide range of healthy gut microbiome, building up resistance and immunity against allergies.
In theory, if diet diversity is introduced early in life (during the first year of life), it can potentially prevent allergies.
Gut microbiome can function as the gut 'gatekeeper' against noxious external pathogens and allergens. Healthy gut microbiome plays a vital role in immune tolerance against food allergens.
Gut lactobacillus may have a role in improving the gut flora and reducing food allergy though the clinical evidence remains limited. The pregnancy days and early infancy days are believed to be the time that can determine gut microbiome pattern and immune tolerance in later life. Healthy lifestyle (pregnant mother and young children) with balance diet packed with fibers, antioxidants, vitamins, good fatty acid helps to build a resilient gut microbiome and immunity, reducing immune system dysregulation and food allergy in later life of the infant.
Mild food allergy symptoms can present in a subtle way with association with recurring gastrointestinal symptoms such as indigestion, bloatedness, diarrhoea, vomiting and one can be confused with other gastro medical conditions.
Other food allergy symptoms include
Localised lip/mouth symptoms:
Symptoms can also involve other organ parts:
Respiratory symptoms
Gastrointestinal symptoms
Skin symptoms
In severe acute food allergy, one can have a catastrophic event known as anaphylaxis. This is a dangerous generalised allergic reaction whereby one can feel sudden closure of the airway, inability to breath, feeling faint, wheezing, whole body rashes, and feeling impending loom. One should seek medical attention immediately as it is a reversible condition, and one can succumb following the delay in allergy treatment.
If you have concerns of possible food allergy, you should consider consulting your healthcare professional. Food allergy can be diagnosed with a good history of exposure to particular food substance and correlation to your symptoms presentation. Having said that, in real world, due to the consumption of various food particles, identifying the food trigger to allergy can be a daunting and confusing task.
Diagnostic options below can be used in conjunction with the history of exposure to nail down the diagnosis of food allergy:
If you’re experiencing symptoms or simply seeking clarity about food allergies, our doctors at Dr. Ben Medical Clinic are here to help. Book a consultation for thoughtful, personalised care tailored to your needs.
References:
Over the past decades, food allergies have become more frequent on both the West and East side of the globe. The presentation pattern of food allergy is slightly different in the Asian group of patients in comparison to the Western populations. While fish and peanut allergies are generally uncommon in Asian population, seafood/shellfish allergy is common in Asian patients experiencing food allergy.
Shellfish food allergy affects approximately 5% of the teenagers in Singapore. Shellfish allergy is one of the leading reasons of food allergy associated anaphylaxis in Asian countries such as Singapore, Hong Kong, Thailand and Taiwan. There is also unique pattern seen in the Asian clinical manifestation of shellfish allergy- intriguingly the allergic symptoms tend to be milder with localised reaction over the oral cavities.
The tropical weather with high humidity in Asia is conducive for house dust mites to thrive and they are practically ubiquitous everywhere we go in Asia. House dust mite allergy remains one of the most common airborne related allergens in Asian patients. House dust mite allergy is associated with a myriad of nuisance symptoms that can affect a person’s quality of life ranging from rhinitis, asthma, to incessant itch, hives and chronic eczema.
In this article, we want to understand the association between house dust mite and shellfish allergies, importantly whether treating the former can exacerbate or improve the latter.
House dust mite allergies are mainly associated with respiratory allergic symptoms, though one can experience abnormal skin symptoms. Symptoms can be acute, occurring within seconds to minutes or less acute, occurring over hours to days after exposure to house dust mite allergens.
Following sensitisation to house dust mites, one may experience
Respiratory symptoms such as
Skin symptoms such as
Shellfish allergy can occur within seconds to minutes upon exposure to shellfish allergens following direct contact of the allergen onto the skin, inhalation of the allergen or consumption of the allergen into the gut system.
Mild allergy symptoms involve localised presentation
One can present with severe abdominal symptoms involving
In life life-threatening condition, one may develop anaphylaxis from shellfish allergy. This is a dangerous medical emergency where one experiences a full-blown allergic reaction – with closing of the airway, facial swelling, inability to breathe, blackout, drop in blood pressure, and widespread body rashes. Immediate medical treatment can reverse and treat such dire situation, however, delay of allergy treatment can result in death.
As the majority of patients with shellfish allergy in Asia tend to present with milder and more stable symptoms, one may even mistake shellfish allergy as gastrointestinal infection, skin inflammatory conditions or other medical conditions.
The main allergen that triggers an allergic reaction in shellfish allergy is tropomyosin, a protein that is involved in contracting muscles in invertebrates. In the shellfish family, tropomyosin can be seen in crustaceans such as shrimp, crabs, lobsters and mollusks such as squid and snail. Interestingly, a highly similar tropomyosin protein is also found in house dust mites, cockroaches.
In view of the presence of similar protein in these living invertebrates, allergy cross-reactivity between house dust mite and shellfish (or even cockroaches) is expected and well documented in clinical literatures. In layman's terms, this means that a person can have house dust mite and shellfish allergies (and cockroaches) concurrently.
As house dust mite can be found in abundance in tropical humid places, it is postulated that the exposure to environmental allergens such as house dust mite and cockroach triggering the first sensitisation to tropomyosin in an allergic person via inhalation of the allergens. Further recognition and sensitisation of the immune system against tropomyosin particles occur in subsequent exposure to shellfish during consumption of the seafood leading to eventual food allergies.
This can be a comparable version of ‘oral-allergy syndrome’ that is commonly seen in the Europe whereby a person who has birch pollen-allergy, may also have cross-reactive allergies when consuming certain fruits and nuts.
Immunotherapy targeting house dust mite has become the game changer in managing atopy conditions associated with dust mite allergies. By re-education and re-challenged of the immune system against dust mite proteins, immunotherapy has proven clinically effective and safe in managing dust mite allergies- in particularly those associated with respiratory allergic symptoms.
The question arises here whether immunotherapy against dust mite allergens can possibly sensitize cross-reactive allergens such as shellfish allergies. Concerns of exacerbation of food allergy following house dust mite immunotherapy treatment due to sensitisation of tropomyosin is also a valid concern.
Hitherto, thankfully clinical studies show no proven new sensitisation of tropomyosin or worsening of shellfish allergy symptoms following dust mite immunotherapy. In fact, there are case studies suggesting potential benefits of food (shrimp) allergy following immunotherapy against dust mites.
Diagnosis of house dust mite and shellfish allergies can be made from a careful and thorough medical history correlating the exposure of the allergens and presentation symptoms. Skin prick tests and blood RAST test can be useful in confirming both house dust mite and shellfish allergies.
If you're experiencing symptoms and wondering whether they're related to dust mites or shellfish, our team at Dr. Ben Medical Clinic is here to support you. Book a consultation to better understand your condition and explore treatment options so you can manage your symptoms effectively.
References:
Atopy refers to a genetic predisposition to developing allergic diseases, while atopic march is the natural progression and evolution of these allergic diseases. Atopy is commonly due to an exaggerated immune response towards allergens in the air or food. Allergic diseases such as atopic dermatitis, allergic asthma and allergic rhinitis affect 1 in 4 people globally, and the incidence of allergy continues to rise over the years.
Allergy diseases are fascinating in the sense that one tends to develop the diseases chronologically from childhood atopic dermatitis and food allergy to eventual progression of asthma and allergic rhinitis. This intriguing allergy progression phenomenon is time-based, involves the evolution and involvement of the skin-gut-respiratory system and is termed the Atopic March.
In this article, we highlight the manifestations in atopic march, the current clinical hypothesis behind these allergic diseases and discuss certain medical strategies to prevent or halt the progression of atopic march.
The initial manifestation of atopic march involves atopic dermatitis, also known as eczema. The atopic march classically continues with food allergy, and eventually ends with progression to allergic asthma and allergic rhinitis. Children with atopic dermatitis have a 6 times higher chance of developing food allergies. 60% of children with atopic dermatitis may eventually develop asthma/ rhinitis later in their childhood.
Atopic dermatitis is a recurring and relapsing inflammatory skin disorder whereby one presents with dry skin, inflamed, and itchy skin. Atopic dermatitis tends to occur in early life. It affects about 30% of children and can manifest its symptoms as early as less than 6 months of age. Atopic dermatitis is due to a complex combination of genetic and environmental factors. It is postulated that due to the impaired skin barrier in atopic dermatitis, external allergens are able to interact with the internal skin and immune cells leading to sensitisation of the immune system and manifestation of allergic response.
Food allergy frequently occurs simultaneously with atopic dermatitis during early childhood and is an indicator and risk of a person to be likely to progress with subsequent atopic march. Children and infants with food allergy develop allergic asthma earlier than those without food allergy. Those patients with food allergy can have an exaggerated and hypersensitivity and inflammation of the airway.
Allergic rhinitis and allergic asthma are two allergic respiratory conditions that are closely linked. Environmental factors such as dust mite particles, air pollution, pollen, pet dander, food proteins/allergens can play a role in the development of allergic rhinitis and allergic asthma.
In allergic rhinitis, there is chronic recurring inflammation of the mucosal layer of the upper respiratory tract with predominant involvement of the nose passage leading to recurring bouts of sneezing, watery and blocked nose, itchy eyes, etc. Recurring allergic rhinitis can also stimulate and trigger contraction of the lower respiratory system such as the lungs muscles and tissues eventually lead to chronic inflammation, spasm and hypersensitivity of the lungs — allergic asthma.
There remain gaps in the understanding of the progression of atopic march. A few theories have been hypothesised to explain the phenomenon.
The skin functions as a physical layer to shield the body against external noxious agents. When the skin barrier is inflamed and impaired, it is ineffective in defending the body against environmental triggers such as pollutants, allergens, infections and other pathogens. The term transcutaneous sensitisation describes the allergenic proteins entering the body via leaky skin, leading to sensitisation of the immune system and development of atopic dermatitis — the first step of the atopic march and subsequent other allergic diseases.
Filaggrin is a protein vital as part of the structure and component of the skin layer (stratum corneum). There is association of genetic mutation of filaggrin protein with those with atopic dermatitis. The integrity of the skin layer is compromised in those with filaggrin gene mutation, causing a weaker skin barrier and, hence, easier access of allergenic protein to the immune system, which can result in atopic diseases.
Airborne and food particles such as dust mites, fungi, pollen, insects, pet dander, peanuts, milk, seafood etc., can behave as allergen proteins. Upon exposure to the skin, gut, respiratory tract, they are able to trigger an exaggerated immune response leading to atopic symptoms.
Interestingly, certain environmental proteins can also function as an adjuvant (facilitator) to other allergenic proteins to cause allergy.
The microbiome in the skin, intestine and the lungs interacts — this is known as ‘inter-organ cross-talk’, and is observed in atopic march. The skin microbiome in a person with atopic dermatitis differs from a person without atopy, with increase in Staphylococcus spp bacteria. It is also noted that the gut microbiome is less diversified in infants with atopic dermatitis and food allergy. The shift of the gut bacteria has been associated with allergic respiratory inflammation. Although the findings in the pattern of microbiome in the human body remain a novel concept, there is strong correlation between alteration of the body’s microbiome and atopic march.
Understanding of the natural progression of atopic march is imperative in managing the progression of atopic march. Although the current understanding of atopic march remains incomplete and there is no easy way to halt the progression of allergy, we can still utilise current clinical knowledge of the disease and manage the allergic progress.
Moisturiser and appropriate topical medication (commonly involving steroids) remain the key backbone in the management of atopic dermatitis. Aside from this ubiquitously known fact, we would like to share tips that are relevant, yet commonly neglected here:
Identifying those who are predisposed to a lifelong chronic atopic disease (atopic march) is paramount as the window period during early life should be targeted for treatment intervention. Maintaining a good skin barrier is essential. Appropriate skin care and management of atopic dermatitis can prevent further sensitisation of food or aero-allergens, subsequently reducing the risk of progression of atopic march.
Managing food allergy, avoiding repeated triggers is beneficial as those with atopic dermatitis and food allergy has shown to be more likely to continue the atopic march progression to the final respiratory allergic symptoms.
While both allergic rhinitis and allergic asthma are considered the end point of atopic march, managing both conditions can improve a person’s quality of life tremendously. The ability to pinpoint the triggering allergens and receive targeted immunotherapy suggest there is a glimpse of hope in managing atopy symptoms.
References:
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Hormones are chemicals that are produced by the endocrine system of the body to maintain the body’s equilibrium known as homeostasis. Hormone levels can fluctuate either physiologically (natural biologically) or due to external factors, such as infection, environmental factors, drugs etc. Interestingly, our hormone levels can affect allergies or predispose a person to allergic symptoms.
In this article, we explore the effects of common hormones, such as sex hormones, thyroid hormones, stress hormones and insulin on common allergies like eczema, allergic rhinitis and asthma.
Sex hormones fluctuate physiologically throughout our reproductive age of life. We may notice our allergy symptoms becoming more prominent or worsen during certain times of our life. Here, we discuss the role of common sex hormones, such as oestrogen, progesterone and testosterone, in affecting a person’s allergy symptoms.
In asthma, oestrogen can bind with oestrogen-receptors on the lung tissues, stimulating inflammation and activation of immune cells in the lungs. Oestrogen regulates chemical protein (chemokine) production, causing mast cells (a type of allergy cell) to degranulate (breakdown), leading to airway cells and airway muscles to be inflamed and becoming overreacting towards allergens. Progesterone hormone prevents mucus clearance from the airway.
In atopic dermatitis (eczema), one is more susceptible to the sex hormones in comparison to those without atopic dermatitis. Oestrogen generally has a positive effect on the skin barrier, reducing the risk of eczema flare ups. Contrarily, both progesterone and testosterone can be detrimental in maintaining a good physical skin barrier, leading to more predisposition of flare up of skin condition under the influence of both hormones.
In allergic rhinitis, the nose tissues and secretory glands can interact with sex hormones, such as estrogen. This, in turn, leads to blood vessels growth, tissue swelling, inflammation and an increased response to allergies and mast cells degranulation. This cascade of activities within the body result in the clinical manifestation of upper respiratory allergy symptoms of rhinitis.
| Allergic Asthma | Atopic Dermatitis | Allergic Rhinitis | |
| Effects of Sex Hormones on allergies | Due to the influence of oestrogen and progesterone, asthma can be exacerbated during peri-menstrual period, pregnancy phase and the exacerbation decline after menopause. Testosterone has an anti-inflammatory effect in asthma conditions. | Due to physiological fluctuation of sex hormone levels during the menstrual cycle, one may notice exacerbation of skin condition just before period or during pregnancy. | Symptoms of allergic rhinitis can be worsened during ovulatory period or during pregnancy period. |
Cortisol, our body’s stress hormone, is produced by a pair of adrenal glands that reside on the tip of both kidneys. The stress hormone is controlled by the brain — hypothalamus and the pituitary.
Stress can result in worsening of allergic symptoms. Generally, stress causes general inflammation of the body. In asthma, stress is responsible for causing lung inflammation and dysregulation of the immune system, leading to susceptibility to allergens and asthma exacerbation. Interestingly, mood disorders such as depression, anxiety and attention deficit hyperactivity disorders are associated with worsening of allergic rhinitis or atopic dermatitis symptoms — hence termed ‘allergic mood’.
Due to the physiological day-night fluctuation of stress/ neuro-hormones, one with atopic dermatitis may notice worsening itch at night.
The thyroid gland is a symmetrical, butterfly-shaped gland situated in front of a person’s neck. The thyroid gland produces thyroid hormones that play essential roles in a person’s overall metabolism. The thyroid levels can fluctuate due to physiological causes, stress, infection, and even autoimmune or brain/pituitary disorders. When the thyroid levels are too high, it is termed “hyperthyroidism”. Conversely, “hypothyroidism” is used to describe thyroid levels that are too low.
Imbalance of the thyroid hormones can exacerbate asthma symptoms. An overproduction of thyroid hormones can cause inflammation, leading to high levels of immune cells and asthma exacerbation. In hypothyroidism, due to slower overall metabolism, there is reduced oxygen usage in the lungs, and slower lung tissue/muscle clearance of air/allergens leading to predisposition of asthma symptoms. Managing thyroid levels back to normal levels can alleviate and aid the overall management of asthma treatment.
Low thyroid level is associated with allergic rhinitis due to reduced mucous/nose tissue clearance of infection/ allergy particles, increased predisposition to various sinus infections and allergies.
While thyroid disorders do not have a direct relationship with atopic dermatitis, low thyroid levels can worsen existing dermatitis as hypothyroidism can cause itching and skin dryness.
Diabetes Mellitus is a chronic endocrine disorder due to dysregulation of the glucose in the body resulting from insufficient or ineffective insulin in the body to process the blood glucose. We discussed the relationship of type 2 diabetes mellitus and allergies.
Type 2 diabetes mellitus is the result of ineffective insulin to break down blood glucose due to insulin resistance over time. Frequently, type 2 diabetes mellitus can be associated with other metabolic disorders such as obesity, which both conditions impair lung function leading to exacerbation of asthma. A good control of type 2 diabetes mellitus can improve a person’s overall asthma symptoms.
The relationship between type 2 diabetes and atopic dermatitis/allergic rhinitis remains much to be elucidated, and clinical literature remains contradictory.
While the association between hormones in our body and allergic symptoms remains an area not commonly discussed, understanding the link between them can potentially ameliorate and manage allergies more effectively resulting in better quality of life.
Importantly, learning the association between hormone fluctuations and allergy symptoms allow both patient and physician to strive towards a more personalised, holistic health management plan to control allergies.
References:
Itching is generally an irritating sensation that results in scratching the affected site. Commonly, itch is associated with infection, allergy, insect bites, or underlying psychiatric conditions, such as anxiety.
Mucosal itches, on the other hand, refer to itch or irritation that occur in the mucosal linings of the body. Simply put, mucosal areas are the connecting junctions between the external skin and the internal body, such as the vagina, anus, mouth, nose, eyes and ears. We tend to neglect the mucosal areas, yet they play a pivotal role in safeguarding our body against external particles, proteins and even harmful pathogens.
The understanding of itching over mucosal surfaces is less discussed. We want to increase the awareness about mucosal itching, the possible causes of mucosal itching at different locations, highlight the common causes and encourage appropriate treatment to the respective conditions.
Itch is often triggered by a stimulus. The stimulus is picked up by sensory receptors over the affected site. These sensory receptors (known as nociceptors) then activate sensory nerve fibres, which are also known as unmyelinated C-fibres. The nerve fibres will transport the stimulus impulse to the spinal cord and the brain, triggering the perception of ‘itch’ and resulting in a cascade of motor reflexes involving scratching the itch site. Interestingly, both pain and itch share the same sensory fibres, and both symptoms can occur concurrently.
The oral mucosa covers the inner cheek (buccal area of the mouth), lips, gums, teeth, the roof of the mouth (known as the palate), the floor of the mouth, tongue and back of the throat. These mucosal regions are highly covered with nerve endings. The maxillary and mandibular nerve from the trigeminal branch supply most regions of the oral mucosa. The back of the oral cavity is also innervated by the vagus nerve.
Provocation of external allergens in the form of airborne or food particles can trigger the sensory nerve endings in the oral mucosa and result in the unpleasant sensation of itch. Often there can be associated nasal hypersecretion symptoms, watery itchy eyes as well
Oral allergy syndrome aka pollen-food allergy syndrome/ latex-fruit allergy syndrome/ dustmites-crustacean allergy
The nose sensation is supplied by the trigeminal nerve. The ophthalmic nerve supplies the mucous membrane over the eyes, nasal sinuses. The ear mucosal areas are supplied by both the trigeminal nerve and vagus nerve. Similar nerve branches also innervate the oral cavity as discussed previously. This rich network of nerves pick up itch stimuli sending impulses to the spinal cord and brain, resulting in itchy sensation.
Similarly, an allergic exposure to the eyes or ears can trigger nasal or even oral symptoms, suggesting the interlinking nervous network of these mucosal areas.
The mucosal region of the vagina is meant to protect the body from external pathogens and facilitate sexual functions. Itch is a sensation meant to be a warning sign to a person that there is an irritation, inflammation or infection brewing. The clitoris, the pubis, vulva, even the cervix has nerve fibers that can stimulate itch sensation. Change in the surrounding temperature, pH, tissue damage, infections can potentially trigger itch nerve signaling and inflammatory response.
Vaginal infection such as yeast (candida) infection can present with vaginal itch. Bacterial STDs such as chlamydia trachomatis, neisseria gonorrhea, trichomonas, mycoplasma genetalium, ureaplasma spp can contribute to vaginal itch.
Hormonal fluctuation, especially lacking in estrogen after menopause can result in itch due to poorer skin and mucosal barrier, and reduced glandular secretion. One may be more predisposed to itch sensation.
Less commonly, yet important not to be missed, itching or pain over the vulva or vaginal area can be due to underlying cancer.
The pudendal nerve is the sensory nerve group found over the sacrum/genital region for both male and female that plays an important role in receiving itch stimuli and result in motor reflex of recurring scratching. Itching over the anal mucosal region is more common in male and it affects 5% of the population.
Mucosal sites are the ‘guardian’ sites that connect the external skin with the internal body. In view of the nature of the mucosal sites, they are covered with large amounts of complex sensory nerves to pick up any potential threat in the form of inflammation, infection or allergy.
Itch over the mucosal surfaces behave like alarm bells of the body, signaling potential external danger. Understanding different mucosal itches at different sites and the possible causes aid correct diagnosis and ensure appropriate treatment to be given.
References:
In Singapore, obesity is defined as a body mass index (BMI) of more than 27.5. Obesity has a deleterious impact on a person’s health — with an increased risk of coronary heart disease, stroke, high blood pressure, diabetes, osteoarthritis, depression, poor sexual function, cancer, and more.
The diet we consume is known to play a major role in the development of obesity. One that consists of mainly processed food and fast food which are high in calories and have minimal proper nutrients. Consuming this diet in the long run can lead to chronic surplus of calories intake, leading to weight gain. Currently, 38% of the people in the world is obese, and this trend is rising continuously.
In this article, we explore the association of obesity and common allergy medical conditions. This article is written in hope of highlighting the importance of managing weight to reduce risk of immunological conditions, hence improving one’s quality of life.
In obesity, there is excessive build-up of fat tissues in the body — a condition known as adipogenesis. The fat cells known as adipocytes increase in size and numbers. The adipocytes produce chemicals and hormones known as adipokines that regulate the body’s overall wellbeing. In obesity, as there are more and bigger adipocytes, more adipokines are produced, leading to disruption of the body's internal equilibrium.
Over time, with excessive adipogenesis, excessive adipocytes and adipokines production, the body is in constant oxidative stress and inflammation. It is postulated that this low grade inflammatory state of an obese person increases the susceptibility towards allergic conditions.
During the chronic inflammatory state of obesity, the gastrointestinal linings also undergo changes. The intestinal microbiome becomes less diverse, leading to a weaker intestinal barrier and increased permeability of food/ protein/ particles/ allergens through the intestine layer. The external proteins or allergens can pass through the intestinal linings into the blood circulation, leading to abnormal activation of the immune system and food allergies.
As obesity contributes to the development of food allergies;
Obesity is clinically shown to increase the risk of allergic rhinitis. However, this association is more seen in the paediatric group rather than in obese adults. Hormone and chemicals such as leptin and interleukin-1beta protein can be found in high levels in obese individuals. These proteins can activate the immune inflammatory response, increase susceptibility towards allergens and increase risk of allergic rhinitis.
It is also hypothesised that due to the pro-inflammatory state of obesity, the mucus membrane lining of the nose passage can be constantly swollen and inflamed, leading to increased permeability of the external allergenic particles which result in activation of the immune system and allergic symptoms in the form of rhinitis.
Interestingly, a person with allergic rhinitis has an increased risk of becoming obese due to hampering of physical activities following rhinitis symptoms or becoming sedentary due to side effects of medications (such as drowsy antihistamines) of rhinitis.
Due to the association discussed above between obesity and allergic rhinitis;
The relationship between obesity and asthma is stronger among the paediatric group with greater risk of developing asthma, more exacerbation of asthma, and harder to manage the condition.
The negative impact of obesity on causing respiratory inflammatory conditions such as asthma is through complex mechanisms. Firstly, there is an innate genetic susceptibility of having asthma. This is further coupled with low grade chronic inflammatory state in obesity, leading to structural changes of the respiratory tract. To make things worse, obesity is also implicated in hormonal changes and less microbiome diversity, leading to predisposition to environmental triggers (pollution/ allergens) of developing asthma.
High sugar and fatty diet in obesity can also reduce the lung function. As excessive fat tissues accumulate around the chest and abdomen, the movement of the lungs and chest wall muscles can be restricted, leading to increased work of breathing.
In a vicious cycle, the repeated use of corticosteroid in asthma or poorly controlled asthma can also cause weight gain. Restricted physical activities may be seen in asthma patients. Weight gain can occur over time with a sedentary lifestyle.
As obesity contributes to the asthma and related long-term comorbidities;
Obesity can affect the skin in a few possible ways. We know obesity promotes inflammatory processes in the body and can affect the hormones and chemical substances of the body.
People with obesity may have an impaired skin epidermis barrier due to increased sweating and increased blood pressure. The skin microbiome can be less diverse in a person with obesity, with more colonisation of Corynebacterium spp. There is less lipid content on the skin surface in an obese person, leading to faster skin dehydration, and increased risk of developing atopic dermatitis. Interestingly, one can have increased risk of developing atopic dermatitis if the mother is obese before pregnancy.
Weight loss has a beneficial effect in overall treatment of atopic dermatitis, hence promoting a healthy lifestyle and weight loss can complement the treatment of atopic dermatitis. Additionally:
References:
Cow’s milk allergy can occur in anyone, including adults. However, it is a condition that more commonly affects the paediatric population. Diagnosis for cow’s milk allergy can be difficult and can often be confused with cow’s milk/ lactose intolerance.
In this article, we’ll highlight the differences and similarities between milk allergies and milk intolerance, the underlying causes of a cow’s milk allergy, common questions that one may encounter, and practical ways to deal with cow’s milk allergy.
No, a milk allergy and milk/lactose intolerance are different.
Milk allergy is an immune response to milk proteins. The body mistakenly identifies these proteins as harmful, producing specific antibodies against it. Upon repeated exposure to these proteins, the immune system triggers an exaggerated antibody response, leading to a cascade of chemical immune reactions, which manifest as signs and symptoms of milk allergy.
A lactose intolerance occurs due to the lack of the enzyme lactase, which is needed to digest lactose — a sugar found in milk. A milk protein intolerance is a non-allergic sensitivity to milk proteins, such as casein or whey.
In milk/lactose intolerance, one develops unpleasant gastrointestinal symptoms when they are unable to digest lactose effectively due to reduced amount of lactase.
The poorly digested lactose in the gut is subsequently being fermented by gut bacteria causing uncomfortable irritable-bowel-syndrome-like symptoms such as:
Contrary to milk or lactose intolerance, an individual with a true milk allergy will not be able to tolerate any amount of milk, while in the case of lactose intolerance, one may still be able to tolerate a small amount of milk.
This type of allergy can occur very fast within seconds to minutes upon consumption of cow's milk. In IgE related allergy response, once the body is exposed to the 'allergen' protein, there will be an immediate trigger of a cascade of inflammatory allergic response and release of IgE antibodies, leading to an acute allergic reaction.
This type of allergy tends to occur slower over a period of hours up to 3 days after consumption of cow’s milk. The immune response tends to develop progressively over time, and usually this is non-IgE related, immune response can often drag on with symptoms for days to even weeks. One commonly confused the symptoms of delayed response with milk/lactose intolerance.
Milk allergy symptoms can occur within the first few months of human life (within the first 6 months of life), though less commonly symptoms can occur in adulthood. There is a spectrum of severity of milk allergy symptoms, making nailing the diagnosis difficult.
Within hours after consumption of milk. Symptoms include:
From hours to days after consumption of milk. Symptoms include:
An immediate, dangerous fulminant allergic response within seconds to minutes after consumption of milk. Symptoms include:
Cow’s milk is a rich source of nutrients for the body, with over 20 beneficial proteins.
In milk allergy, the body's immune system reacts to protein that is found in the milk, particularly in 2 types of proteins — casein and whey.
Casein protein is the main emulsifier in milk and it makes up 80% of the protein in cow’s milk and 20-60% of proteins in human milk. Casein is also found in high quantities in cheese, and can be used as a food additive/ emulsifier to stabilise processed food.
Whey protein is the left over from milk when it is coagulated during the formation of cheese. Whey protein makes up 20% of cow’s milk, and about 60% of human milk. Whey protein is made up of 2 major proteins known as alpha-lactalbumin, beta-lactoglobulin.
Whey protein is commonly seen in yoghurt and protein supplement (in building muscle mass). Whey protein can also be used as a food thickener.
Common foods with milk protein include:
Reading food labels is important to pick up any cow’s milk protein content. If you are eating out, beware of possible milk in the food content.
Extra caution should be taken if eating out in coffee shops, pizza shops and ice cream places. If in doubt, it is worth highlighting any history of food allergy or food restrictions to the restaurant staff.
A good history with a clear timeline of exposure to milk allergens and presentation of the allergic symptoms is suggestive of cow’s milk allergy. Nonetheless, in the practical world, this can be much more difficult as one may be exposed to other food substances or environmental allergens or symptoms can be confounded with underlying intolerance.
Allergy tests may not be foolproof either, but may facilitate the history of presenting complaints:
You are advised to discuss any concerning symptoms with your doctor so that they can provide guidance on which tests can be offered to you to evaluate your condition further.
As there are no antidotes for cow’s milk or food allergies, the treatment is by eliminating the culprit allergen — milk from the diet.
In situations when one has inadvertently consumed milk, medication such as antihistamine and steroid can reduce or abort allergic symptoms. In severe allergic response or anaphylaxis, one will require adrenaline injection or medical emergency to reverse the allergy.
As cow’s milk allergy is commonly seen in children, it is imperative to ensure the child still receives a healthy balanced diet and is taking supplements to replace the common nutrients that are found in milk.
Breastfeeding is encouraged especially if the infant has cow’s milk allergy.
As cow’s milk protein can be passed from mother who consumed it to the child through breast feeding, the mother should avoid food that contains cow’s milk protein if the infant has cow’s milk allergy.
Alternative options such as soy formula milk may not be useful as some children may also have soy protein allergy. Due to high protein allergy cross-reactivity, those with cow’s milk protein are usually not suitable to take goat’s milk as well.
Understanding and determining the allergic components in milk proteins can aid prudent food selections to avoid allergy.
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Allergic rhinitis (AR) is a common inflammatory airway disorder triggered by airborne-related allergens. While this is not a life-threatening medical condition, it can be debilitationg — affecting a person’s quality of life; causing poor quality of sleep, suboptimal work performance and social interaction impairment.
In this article, we want to understand the background science and immunology of allergic rhinitis and make sense of the current treatments available, including the exciting option of immunotherapy.
Allergic rhinitis is an upper airway disease resultant from sensitisation of allergens and proteins in the air during breathing. The classical symptoms involve the upper respiratory airway such as sneezing, nasal itch, increase nasal secretion, blocked nose and etc. Common inhalant allergens that can trigger allergic rhinitis include house dust mite particles, mould, animal dander, grass, birch and pollen, cockroach particles and more.
In allergic rhinitis, following exposure to allergens, the immune response undergoes 2 phases:
The inhaled allergen protein will be ‘carried’ and ‘presented’ by a type of specialised cells known as Antigen Presenting Cells (APCs) to the nearby lymph nodes. Lymph nodes are ‘checkpoints’ in our body that store immune cells.
The allergen proteins then trigger a cascade of inflammatory response from the immune cells. Immune cells that are commonly involved in this phase include T cells, B cells, IgE antibodies, mast cells, ILK-4, IL-13, histamine, prostaglandins, leukotrienes, TNF-alpha and etc.
Following 4-6 hours of exposure to allergen protein, there will be further chemical inflammatory response involving cells such as monocytes, granulocytes, protein elastase and etc.
*Understanding the involvement of immune cells is imperative as this becomes the target area of modern medicine in allergic rhinitis.
The surge of inflammatory response in the early and delayed phase can be translated to the clinical symptoms of allergic rhinitis such as acute sneezing, itching, runny and block nose. Symptoms tend to abate when the allergen is withdrawn or avoided.
Over time, with recurring exposure and recurring inflammatory immune response, repeated wax and wane of condition, remodeling of the affected airway can occur. This explains the association of chronic allergic rhinitis with more complicating ENT conditions such as nasal polyps, nasal hyperplasia, eosinophilic sinusitis and more.
Interestingly, allergic rhinitis can be associated with asthma and chronic rhinosinusitis. The actual cause of association remains not fully understood. However, in these conditions, when one is exposed to allergens, there are similar inflammatory immune response demonstrated.
Statistics show 10-40% of people with allergic rhinitis have concurrent allergic asthma, while 60-80% of asthma people have concurrent allergic rhinitis. In chronic allergic rhinitis, when there is repeated and resolution of airway inflammation, remodeling of the airway anatomy can result in chronic rhinosinusitis or nasal polyps and other ENT conditions.
The ideal treatment of allergic rhinitis is to eliminate the triggering allergen from the environment. This, unfortunately, even with strict lifestyle allergenic control is not achievable and not practical.
Current management of allergic rhinitis involved a holistic approach of combining modern medicine with lifestyle control of environmental allergen to alleviate the condition.
Despite current conventional treatment is beneficial in controlling symptoms of allergic rhinitis, one may find taking daily pills, nose sprays or nasal irrigation a challenge and burden to our daily living.
In addition, the symptomatic medications may even be limited in efficacy in some patients. To address these concerns, immunotherapy can be considered as a potential therapeutic option.
Not all patients with allergic rhinitis find conventional medical treatment useful. Allergen specific immunotherapy (AIT) may come in useful and serve as a safe alternative treatment. AIT is a desensitization treatment where the triggering allergen is repeatedly introduced to the affected person over time to modify the immune response, inducing desensitization and amelioration of allergic symptoms after exposed to allergen.
AIT is arguably to achieve immune tolerance against allergen in the affected person over time following repeated re-exposure. In immunology terminology, with repeated exposure to the allergen, the body is able to normalised its own immune and inflammatory cells, preventing them from being triggered by allergens. AIT also produces allergen-neutralising antibodies that prevent allergen from triggering allergic inflammatory response. In clinical setting,
Here, we can observe the treatment of allergic rhinitis has shifted from conventionally controlling symptoms with symptomatic medication to management and re-education of the immune response to an allergen, hence transforming the immune system that is exaggeratingly overactive to 'normal' immune reaction towards allergen protein.
It is worth to note that in order to consider AIT, it is mandatory to identify the specific culprit allergen that causes the symptoms. Thankfully, again with modern medicine and technology, many of the common allergens can be picked up with skin prick test or IgE RAST blood test.
Medical literature over the years has shown consistently that AIT is useful in alleviating allergic rhinitis symptoms and standard medication burden. Currently, AIT can be considered in allergic rhinitis patients with specific IgE allergy that present with significant symptoms that affect their daily life, sleep despite conventional pharmacological treatment.
AIT demonstrates effective management of allergic rhinitis with concurrent allergic asthma. AIT has shown clinical significance in reduction of both allergic rhinitis and asthma symptoms, asthma exacerbations and hospitalisation. AIT also shows good clinical improvement in those with allergic rhinitis and concurrent rhinosinusitis disorders.
Furthermore, AIT when introduced during the early phase of allergic disease can prevent progression of allergic rhinitis to asthma or new allergen sensitisation. This is particularly useful and a beneficial option for the younger group people with allergic rhinitis. This can also serve as a backbone theory in further research and medical advancement into immuno-desensitisation related treatment.
References:
Consuming seafood has become a popular food choice globally. However, there have been increasingly reports of adverse health reactions following consumption of seafood. A body’s adverse reaction towards shellfish can be allergic-related vs toxic-related.
Allergies to seafood or shellfish is one of the common food allergens that occur in both children and adult. Interestingly, one with shellfish allergies tend not to outgrow from childhood. Shellfish allergic symptoms tend to be more severe when compared to other food allergies. Shellfish allergy affects approximately 0.5-2.5% of populations, though the actual cases of shellfish allergies are likely under-reported or un-diagnosed.
While one can have true allergic reaction following consumption of shellfish, the body can also react badly as a result of toxins and infections from eating shellfish. Shellfish can also be contaminated by bacteria such as salmonella spp, vibrio cholera, listeria spp. These noxious bacteria when consumed into human body, have capabilities to release toxins to the bloodstream and trigger a cascade of inflammatory and infective response.
Understanding one’s clinical presentation and underlying the cause of adverse reaction to shellfish can be important in determining subsequent management and prevention of similar detrimental health symptoms.
Although 'seafood' and 'shellfish' are both used loosely, interchangeably and ubiquitously, they may have different meaning. 'Seafood' is an umbrella term to include any 'edible particles found in the sea', while 'shellfish' includes those with 'shells' as part of their skeletal system.
The shellfish family can be sub-categorised into crustaceans and mollusks.
Allergies occur when the body's immune system is exposed to a substance (known as allergen) that is generally harmless. The immune system overreacts and produces excessive inflammatory response leading to clinical manifestations of allergic symptoms.
The onset of shellfish allergic symptoms tends to be within seconds to minutes with involvement of the skin, airway and gastrointestinal system. There can be an array of clinical presentation:
In very severe cases, one can succumb to shellfish allergy due to development of life-threatening anaphylactic reaction. Anaphylaxis presents with generalised involvement of allergic symptoms with feeling of 'impending loom', fainting spells, tightening of airway, facial swelling, difficulty of breathing, wheezing and widespread body rashes. Immediate medical attention can reverse such situation, and delay of treatment can result in death.
One can also develop allergic symptoms following the inhalation or direct touching of the shellfish protein allergens. This can occur in fish handlers, or one who works in kitchen preparing shellfish meal, leading to sensitisation of the airway and the skin. In such cases, one can present with wheezing, asthma symptoms or itchy hives rashes upon close contact with shellfish. Hence, shellfish allergy can develop even without consuming shellfish.
Tropomyosin is the main allergen found in shellfish that plays a vital role in shellfish allergies. Tropomyosin is a protein found in the muscle cells. It can be found in shellfish in both crustaceans and mollusks.
One can have cross allergy reactivity between the shellfish family. For example, one may be allergic to crustaceans such as crab and also present allergic symptoms when consuming mollusks such as clam. Tropomyosin is stable to heat- hence one can still develop allergic symptoms after consuming shellfish that is boiled or cooked with heat.
As tropomyosin allergen can also be found in dust mites, cockroach particles, parasites and insects, there can be cross allergy reactivity between these substances. A person with shellfish allergy can have concurrent allergy towards dust mites, insects, parasites and etc, vice versa.
Thankfully, those who has shellfish allergies usually do not have fish allergies as there is no cross reactive protein allergens between the two groups although both are aquatic edibles. The belief that shellfish allergy is due to iodine is untrue, hence one with shellfish allergies does not have increased risk of radiocontrast iodine allergy.
Other allergens that are found in shellfish include arginine kinase, myosin light chain kinase, and sarcoplastic calcium binding protein which can cause allergy reaction in the children group.
While we tend to assume shellfish adverse reactions are due to an allergic response, one may have similar unpleasant symptoms due to shellfish poisoning.
Shellfish poisoning or shock syndrome can present with symptoms mimicking an allergic reaction depending on the amount of shellfish and toxin concentration ingested. Symptoms, within minutes of consumption of poisonous shellfish, include:
In more severe cases, neurological symptoms such as numbness and weakness of face, neck, arms and legs, or even paralysis up to 72 hours may occur. Shellfish poisoning can also be associated with headache, confusion and short-term memory loss.
Occasionally, adverse symptoms associated with shellfish may not be the poison directly from shellfish. Shellfish can be contaminated with bacteria such as vibro spp, clostridium botulinum, staphylococcal spp, salmonella spp or even Norwalk virus that can present itself with acute gastrointestinal symptoms such as nausea, vomiting, diarrhea, or even fatality.
If you have concern of shellfish allergies, you are encouraged to discuss your symptoms and concerns with your health care providers for further guidance on diagnosis and management of your symptoms.
Allergies are exaggerated immune response towards allergens — substances that are usually not dangerous to the body. Allergy disease can be triggered by particles from the environment such as food, air pollutants, mould, mites, fur, medications, chemicals and etc.
As the worldwide populations are getting older, there are increasingly presentation of allergy conditions among the aged population. Allergy in the elderly is starting to emerge as a health issue. With rising age, ageing physiological changes will inevitably occur, with increase chances of developing chronic conditions including allergies.
Occurrence of allergy in elderly can be due to immunosenescence — a process of physiological ageing of the immune system. This can be seen with progressive modification and ageing of the body tissue structure and immune system. The process of immunosenescence can also be further accelerated with concurrent medical conditions, drugs, and environmental factors.
Although allergy conditions are becomingly common in the elderly, it is a topic less discussed and thought of. This article is written in hope to increase awareness of allergy conditions in elderly, highlighting the possible clinical presentations and encourages readers to seek medical advice and treatment if there is a concern of chronic symptoms associated with allergy.
As we progress with time and age, the body undergoes constant changes. Our cells, tissues, organs and body system’s physical structure and function deteriorate as we grow old. The gradual physiological dwindling of human can result in increased susceptibilities towards
infections, cancer, inflammation and allergy response.
In addition, micronutrients such as vitamin D, zinc, iron which are imperative in maintaining the immune system, tends to be inadequate in the older age group. These further result in a deleterious impact in the elderly’s health, potentially present itself as allergies or immune-related diseases.
As time goes by, the intestines have weaker general immune response, a higher permeability to particles and allergens and a slower gastric digestive ability. These physiological progress can further be altered by various medications that one may be taking due to other elderly chronic conditions. Poorer and ineffective digestion, persistent allergen proteins in the intestine, impaired intestinal barrier and increase permeability of the allergens can lead to abnormal immune response and allergies.
Allergy presentation of the gut
As we grow older, the structure and physiological changes of the alimentary system increases risk of food allergy in the elderly. Food allergy is often under-reported and under-diagnosed in the elderly. Clinical symptoms of food allergy in the older population can be slightly different from the younger or paediatric group. One can present symptoms later (rather than immediate) following consuming food substances that they are allergic to.
There can be a wide range of symptoms severity. One can have:
to more severe symptoms such as:
Occasionally, systemic symptoms such as skin itch, hives, rhinitis, sneezing, wheezing or asthma can be associated with food allergies.
Common food particles that can trigger allergic response in elderly include seafood or shellfish, nuts, fruits, vegetables, alcohol and etc.
The upper respiratory system and lower respiratory system of our body undergoing physiological ageing process. The internal linings of our nose, sinuses, upper airway tracts are covered with small nose mucosal cells known as the mucocilliary cells. These cells secrete mucous and trap external proteins and particles, allergens, pathogens and transfer them towards the throat/gullet and eventually cleared by our digestive system. As we grow older, these mucocilliary cells become less effective, leading to accumulation of mucus secretions, and reduce ability of the respiratory system to fight against infections and inflammation. Due to further repeated damaging of the mucosal cells from repeated respiratory infections over the years, the function of these mucocilliary cells even further deteriorate with time.
In the lungs, with age, the lung cells progressively loss its lung function resultant in less elastic lung tissues, weaker lung muscles, impaired airway barrier, less effective gas exchange in the lungs, increase in overall work of breathing and increase susceptibility to sensitisation of environmental allergens.
Allergy presentation of respiratory system
Exposure to environmental factors such as allergens, infections, pollution, can cause chronic inflammation of the airway tissues and mucosal cells. As time goes by, one can be sensitised towards allergens and present with recurring and intermittent rhinitis symptoms, such as:
Rhinitis in the elderly is commonly not addressed as it is not considered a life-threatening disease and there may be other concurrent health issues that is considered more ‘pressing’ or ‘important’. However, rhinitis can affect a quality of life — consequently in taking time off from work, polypharmacy and increase overall health care costs.
Asthma is a chronic inflammatory disease of the airway that can be genetically predisposed and can be further exacerbated and triggered by environmental caused such as allergies. Although asthma is a condition that tends to occur since young, late onset asthma can occur in older age groups. Persistent lower respiratory symptoms such as cough, wheezing, chest tightness, difficulty in breathing should warrant one to consider diagnosis of asthma and possible underlying allergies.
Common airborne allergens include dust mites, cockroach, pollen and grass, mould, animal dander and etc. Understanding possible allergies that contribute to chronic respiratory diseases can be beneficial to the elderly in symptoms and disease control.
As the skin ages, both the skin layers of epidermis and dermis get thinner. There will be slower skin turnover, loss of collagen and normal skin structure, resulting in impaired skin barrier. The aged skin gets dehydrated easier, increase permeability to environmental stressors, particles and allergens. Over time, the skin has less ability to respond to external stressors due to poorer skin integrity.
Allergy presentation of the skin
Itching is one of the most common sign and symptom that elderly patients can present in clinic. This can be associated with symptoms such as rash, blistering, pain and etc. These symptoms may seem mild and ‘unimportant’, though they can be presentation of an underlying skin allergy. The elderly are prone towards skin conditions such as eczema, contact dermatitis, hives (urticaria), drug allergies and etc.
If you or your elderly family member have concerns of having an allergy, you are encouraged to speak your doctor on your symptoms. Sometimes, allergies may be able to be identified from history of exposure. However, in those that the allergies are not ascertained from the history, your doctor may offer you allergy tests to evaluate the allergies further.
Allergy tests such as skin prick tests or blood RAST test may be useful in further understanding a person’s allergies.
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