Dr. S. Yung, Allergist

Allergy & Asthma Specialist in York Region


Environmental Allergy FAQs

What is an allergy?

An allergy occurs when the body's immune system tries to fight something that is normally not a threat, such as pollens, pets, food, insect stings and drugs (called "allergens"). Antibodies (IgE) form in the body which recognize allergens upon exposure, triggering allergy symptoms.

What are allergy symptoms?

Common symptoms of environmental allergies ("hayfever") include:

  • Nose: itchy, runny, stuffy, sneezing
  • Eyes: itchy, watery
  • Sinus pressure/headaches
  • Worsening cough/wheezing (with asthma)

What are the allergy seasons?

"Hayfever" or environmental allergies can be divided into seasonal (spring, summer, fall) or perennial (year round). The time of year someone experiences symptoms can be a clue to their allergies. In the Greater Toronto Area:

  • Spring/early to mid summer: tree and grass pollens
  • Late summer through the fall: ragweed pollen
  • Year round: common allergens are dust mites, cockroach, molds, animal danders

Note that this is rough guide. Allergy testing can be helpful in identifying specific allergies so that management can be tailored to the person.

How do I find out if I have allergies?

An allergist can diagnose allergies by asking about symptoms and performing allergy testing (usually skin testing but sometimes bloodwork) to determine what allergies (if any) someone may have. Environmental allergy testing may include pollens (trees, grass, weeds), molds, dust mites and animal dander (cat, dog, horse, etc.).

What treatments are available for environmental allergies?

1. Antihistamine pills/liquid: Non-sedating antihistamines are used to treat environmental allergy symptoms such as itchy/watery eyes and runny nose. These work by blocking the action of histamine which is a chemical that causes these symptoms. There are over-the-counter and as well as prescription antihistamines available in Canada.

2. Nasal steroid spray: A doctor may recommend a steroid nose spray ("intranasal spray") instead of or in addition to antihistamines. These work by decreasing the inflammation in the nose. In Ontario, these are available both over-the-counter as well as by prescription.

Note that these are NOT decongestant nose sprays. Decongestant nose sprays should be used with caution as they can lead to worsening nasal congestion if used for more than 2-3 days and then stopped. For more information, ask your physician or pharmacist.

3. Combined nasal steroid and antihistamine spray: An example is fluticasone propionate and azelastine hydrochloride. This spray provides combined antihistamine and anti-inflammatory effects in the nose. In Ontario, it is available by prescription only.

4 Allergen immunotherapy for environmental allergies:

"Allergy shots" or under-the-tongue tablets are available for certain allergies. These work by giving someone a bit of what they are allergic to (either by injection or under-the-tongue) so that over time their body "gets used to" the allergen. Unlike other treatments which target symptoms, immunotherapy is the only treatment that targets the underlying abnormal immune response to allergens. Talk to your allergist to see if immunotherapy is right for you.