Does Allergy Change With Time?

Allergies fluctuate with time. Symptoms of allergy can wax and wane as time goes by as well. One may notice their allergy symptoms change over time, with some noticing the symptoms are gone, or worsening as they grow older.

This article aims to highlight to readers on the dynamic state of allergies, enlighten readers on both innate and environmental factors that modulate allergies, discuss the role of allergy testing (or repeat testing).

Why does allergy change with time?

Just like the human body, a person's response towards allergy is dynamic. Allergy is an exaggerated response of the immune system against innocuous proteins in our surrounding, resulting in excessive inflammatory response of the body. This manifest itself with allergic symptoms such as runny nose, body rash, sneezing, hives, anaphylaxis and etc. The immune system is able to adapt (for the better hopefully) and change (for better or worse) with the repeated or reduced exposure of allergen proteins.

While the mechanism of allergy fluctuation is complex and not fully understood, we can narrow down some factors that can affect a person's allergy over time.

Inherent Causes

Genetic Susceptibility

Predisposition towards allergy, a condition known as atopy, can run in the family. Our genes programmed since birth and inherited from our parents and family can play a role in the development of allergies. One with atopy has an inborn tendency to develop allergic conditions such as atopic dermatitis, allergic rhinitis, food allergies and allergic asthma.

Immune system

Our general immune system is also responsible in the manifestation of allergy. Our immune system adapts and fluctuates with the surrounding. Due to repeated exposure or declined exposure to allergens, our immune system changes over time for better or worse in response to these exposures. As we progress with age, the immune system declines, a condition known as immunosenescence. Inevitably, one becomes more at risk of developing allergies (even if one may not have allergies in the younger days). One of the examples include newly developed food allergies ageing individuals due to declining function of the gastrointestinal system when growing older.

Hormones

Endocrine changes during puberty, pregnancies, menopause or even pure stress can be triggers towards allergy symptoms as well.

Sex hormones such as estrogen, progesterone and stress hormones such as cortisol can influence the immune cells, causing the release of histamine which manifest as allergy symptoms.

Environmental factors

Interestingly, to develop an allergy, one needs to be firstly exposed to the allergen protein- either by touching/ contact, consumption or even inhalation. Overtime, the body starts to recognize the 'allergenic protein', remember and build 'memory immune cells' against the allergen protein and mount inappropriate inflammatory response resulting in allergic symptoms. Repeated exposure towards allergenic protein can affect the body's immune response towards the allergen and manifest as allergic symptoms over time.

Infections

Infections in particular respiratory viral infections can exacerbate allergy symptoms by promoting sensitisation towards the allergen, activating airway inflammatory pathways. Clinically, this is commonly seen in airway inflammatory disorders such as allergic asthma, bronchitis or bronchiolitis.

Pattern of Airborne Allergies Changes Over Time

Airborne allergies may be dependent on the geographical residence. One who lives closer to the equator, with hot humid tropical climate like Singapore may notice prevailing allergies towards house dust, dust mites, and mold spores. Compare to those who lives in seasonal countries, allergies such as hay fever or pollen allergies are more commonly seen.

Due to migration and foreign travel, one may notice alleviation of certain inhalant allergies and potential development of new airborne allergies that are unique to the local geographic area.

Pattern of Food Allergies Changes Over Time

Some food allergies can be transient, with one able to outgrow and tolerate the allergenic food over time, while others may notice certain food allergies persist through childhood into adulthood and later part of their lives.

Thankfully, pediatric allergy of common staple food proteins such as cow's milk, wheat, soya, eggs tends to resolve or improve as the child grows up. Reassuringly, 80-95% of the infants may even outgrow these allergens when they reach 5 years of age.

Food proteins such as tree nuts, peanuts, seafood, shellfish are common triggers for food allergies and tends to persist as lifelong allergies in susceptible person.

Role and Indication of Repeating an Allergy Test

Able to identify the triggering allergen that causes allergy is key in management and prevention of further allergic episodes. Furthermore, allergy can change (worsen or improve) over time. While we can gauge our allergy symptoms clinically based on symptoms, the culprit allergens behind the symptoms may be difficult to pinpoint solely based on history.

Laboratory allergy tests can serve as validated tools to understand whether existing allergy has resolved over time, rather than opting for more drastic option such as direct food challenge tests which can potentially trigger an allergic reaction in the case of food allergy.

Allergy tests allow us to be warned, prepared, to take proactive steps to avoid particular allergens. In some where allergens are unavoidable, re-challenge and re-education of the immune system with immunotherapy may be beneficial in long term management and remission of allergy symptoms.

There are generally no strict guidelines on frequency of allergy testing. Having said that, due to the transitional changing nature of allergy and body's immunity, follow up allergy retesting 2-3 yearly can be useful to monitor for allergy changes.

How can Allergy Tests be done?

Allergy tests can be offered with skin prick tests or IgE RAST tests depending on your allergy symptoms and medical history.

Allergy tests together with your symptoms and physical examination can aid your doctor to come up with the right diagnosis.

IgE allergen specific tests: This is a blood test whereby a person's blood sample is drawn and sent to the laboratory to measure the levels of IgE antibodies produced by exposure to certain allergen. It is useful in those that are not able to tolerate skin prick tests due to skin medical conditions or consuming certain medications.

Skin prick tests: This is a test whereby your physician will introduce the allergen protein onto your skin via a tiny needle pricking. A bump or swelling may develop over the site of testing.  It is a useful quick test to evaluate for allergies.

You may wish to discuss with your doctor on which type of allergy test is more suitable for your condition before proceeding with the tests.

Afterwords...

• Allergies can change overtime, the course of allergic symptoms can be unpredictable.
• Genetics, immune system, hormones environmental factors can affect the outcome of allergy symptoms as time progress.
• Allergy testing at suitable interval depending on individual symptom changes, exposure, lifestyle and general wellbeing can be useful in identifying dynamic allergies and allow one to take precautionary personalized measures in managing allergy.

Contact DB Clinic

If you’ve noticed changes in your allergy symptoms over time, a proper medical assessment can help clarify what’s happening and why. At Dr Ben Medical, our doctors take a personalised approach to understanding allergy patterns and triggers. You may book a consultation to discuss your symptoms and explore appropriate next steps.

References:

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2. Foong RX, Santos AF. Biomarkers of diagnosis and resolution of food allergy. Pediatr Allergy Immunol. 2021 Feb;32(2):223-233.
3. Berin MC. Mechanisms that define transient versus persistent food allergy. J Allergy Clin Immunol. 2019 Feb;143(2):453–457.
4. Shin JH, Lee DH. How does the pattern of aeroallergen sensitization change over time across all ages? Int Forum Allergy Rhinol. 2017 Jul;7(7):652-659.
5. Martinis MD, Sirufo MM,Ginaldi L. Allergy and Aging: An Old/New Emerging Health Issue. Aging Dis. 2017 Apr 1;8(2):162–175.