Outdoor Allergies

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.

Types of Outdoor Allergies

Outdoor allergies that are commonly seen include:

(1)Pollen

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. 

(2) Mold spores

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.

(3) Dust mites

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.

(4)Pet dander

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. 

(5) Insects venom

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. 

Who can be affected with outdoor allergies? What are the implication of outdoor allergies? 

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.

What are the common outdoor allergy symptoms that one may encounter?

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:

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.

How can I investigate for possible outdoor allergies?

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

• Skin Prick Tests: introducing the allergens onto the skin (into the dermis layer) and monitor for any allergic reaction such as hives etc.

or

• blood RAST tests: by drawing blood serum, to detect IgE antibody level against an allergen. 

If you have concern of suffering from outdoor allergies, you should consider speaking to your healthcare providers for further evaluation of your symptoms.

What can I do to manage and minimize the outdoor allergies?

What can I do?

• If your house/ living space is close to nearby outdoor greens/ park/ garden, worth keeping the windows closed at night.
• Consider air purifier to keep indoor living space clean, and limit the amount of airborne allergies- including pollen/mole allergies
• Upon returning indoors from outdoor activities, do shower, shampoo your hair and change off outdoor clothing to reduce the body persistently exposed to outdoor allergens.
• Avoid drying cloths, linens or sheets outdoor to dry.
• Avoid taking up the job of mowing the lawns in your gardens.
• Ensure your car windows are closed if you are travelling in a vehicle.
• Using insect repellents, mosquito patches may aid warding away unwanted insects during outdoor activities.
• Consider closely follow up with local news sources such as the National Environment Agency (NEA) website in Singapore on pollen and mold count in the local vicinity. 

What can my physician do for me?

If your allergy symptoms are persistent, your healthcare providers may prescribe

• Antihistamines
• Steroid medication in the form of tablets, creams, eye drops, or event shot depending on the severity of the allergy
• In dire/ life threatening circumstances, your doctor may prescribe adrenaline to reverse and abort the allergies
• In certain chronic nuisance allergic situation, allergen-specific immunotherapy can be offered to desensitize and de-escalate the allergic symptoms progressively.

Role of immunotherapy in outdoor allergies

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.

What have I learnt today?

• Outdoor allergies are present and rising even in urban living metropolitan places like Singapore.
• We can be exposed to common outdoor allergens such as pollen and grass, mold and fungi, dust mites and pet dander, insect bites.
• Outdoor allergic symptoms when not managed, can result in health morbidities and negative social consequences.
• Outdoor allergic symptoms can affect various body parts, in severe cases, can even result in catastrophic life threatening anaphylaxis.
• History and allergy tests are useful in diagnosing outdoor allergies.
• While lifestyle management is ideal in management of outdoor allergies, often this may not be practical and medical management is warranted.
• Antihistamine, steroids, adrenaline remains the backbone treatment management in acute allergic symptoms- including outdoor allergic symptoms.
• Immunotherapy can be beneficial in long term management of outdoor inhalant allergies.

Contact DB Clinic Today

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!

References:

1. Stevanovic K, Sinkkonen A, Pawankar R, Zuberbier T. Urban Greening and Pollen Allergy: Balancing Health and Environmental Sustainability. J Allergy Clin Immunol Pract. 2025 Feb;13(2):275-279.
2. Creticos PS, Gunaydin FE, Nolte H, Damask C, Durham SR. Allergen Immunotherapy: The Evidence Supporting the Efficacy and Safety of Subcutaneous Immunotherapy and Sublingual Forms of Immunotherapy for Allergic Rhinitis/Conjunctivitis and Asthma. J Allergy Clin Immunol Pract. 2024 Jun;12(6):1415-1427.
3. Pavon-Romero GF, Parra-Vargas MI, Ramirez-Jimenez F, Melgoza-Ruiz E, Serrano-Perez NH, Teran LM. Allergen Immunotherapy: Current and Future Trends. Cells. 2022 Jan 8;11(2):212.
4. Singh M, Hays A. Indoor and Outdoor Allergies. Prim Care. 2016 Sep;43(3):451-63.
5. Tham EH, Lee AJ, Bever HV. Aeroallergen sensitization and allergic disease phenotypes in Asia. Asian Pac J Allergy Immunol. 2016 Sep;34(3):181-189.
6. Andiappan AK, Puan KJ, Lee B, Nardin A, Poidinger M, Connolly J, Chew FT, Wang DY, Rotzschke O. Allergic airway diseases in a tropical urban environment are driven by dominant mono-specific sensitization against house dust mites. Allergy EAACI. 2014 April; 69(4): 501-509
7. Burge HA, Rogers CA. Outdoor allergens. Environ Health Perspect. 2000 Aug;108(Suppl 4):653–659.