Allergies in Canada: Symptoms, Causes & Treatment (2025)

Allergies in Canada affect approximately one in five people, making them one of the most common chronic health conditions across the country. They occur when your immune system overreacts to a normally harmless substance — such as pollen, pet dander, dust mites, or certain foods — triggering symptoms that can range from mild to severe.

Understanding Allergies in Canada: Causes and Risk Factors

Understanding the allergy symptoms, causes, and treatment options available to Canadians is the first step toward effective relief. Whether you experience seasonal allergies during spring and fall or deal with year-round triggers, this guide covers everything from diagnosis methods to immunotherapy and natural approaches used by Canadian healthcare providers.

What Are Allergies?

Common Types of Allergies in Canada: Characteristics and Management

Allergy Type	Common Triggers	Key Symptoms	Management Approach
Seasonal Allergic Rhinitis (Hay Fever)	Tree pollen (birch, alder), grass pollen, ragweed — highly prevalent across Canadian provinces	Sneezing, runny nose, itchy watery eyes, nasal congestion	Antihistamines, nasal corticosteroid sprays, allergen immunotherapy
Food Allergies	Peanuts, tree nuts, milk, eggs, wheat, soy, sesame, fish, shellfish, mustard (Canada’s 14 priority allergens)	Hives, vomiting, swelling, difficulty breathing, anaphylaxis	Strict avoidance, epinephrine auto-injector (EpiPen), emergency action plan
Insect Venom Allergy	Bee, wasp, hornet, and yellow jacket stings common throughout Canada	Localized swelling, hives, dizziness, anaphylaxis in severe cases	Epinephrine auto-injector, venom immunotherapy, medical alert bracelet
Pet Dander Allergy	Cat and dog dander, saliva, urine proteins; affects approximately 20% of Canadians	Sneezing, itchy eyes, skin rashes, asthma exacerbation	HEPA air purifiers, antihistamines, allergen immunotherapy, pet-free zones
Mould Allergy	Indoor and outdoor moulds; elevated risk in humid Canadian climates and older housing	Nasal congestion, coughing, wheezing, throat irritation	Dehumidifiers, mould remediation, nasal corticosteroids, antifungal treatment if indicated

An allergy is your immune system’s overreaction to a substance called an allergen. Your body treats it like a threat, even when it is not dangerous. As a result, your immune system releases chemicals that cause allergy symptoms.

Most people develop their first allergy symptoms in childhood. However, allergies can appear at any age. Research also shows that allergies often run in families. If one or both parents have allergies, their children are more likely to develop them too.

Emotional factors such as stress, anxiety, and frustration can also make allergy symptoms worse. Therefore, managing your mental health can be an important part of managing your allergies. Health Canada provides general guidance on managing chronic conditions, including allergies.

Common Allergy Symptoms

Allergy symptoms depend on where in the body the reaction occurs. Symptoms can range from mild and annoying to serious and life-threatening. Here is a breakdown by body area.

Nose and Airways

When allergies affect your nose, the condition is called allergic rhinitis — often called hay fever. Symptoms include a runny or itchy nose, sneezing, and nasal congestion. Many Canadians deal with this condition every spring and fall when pollen counts are high.

When allergies affect the lungs, they can trigger asthma. Asthma symptoms include shortness of breath, wheezing, a tight chest, and a dry cough. Asthma is especially common in Canadian children who are exposed to pet dander or mould.

Eyes

Allergies can also cause red, itchy, and watery eyes. Your eyelids may swell and feel uncomfortable. This is sometimes called allergic conjunctivitis. It often happens at the same time as nasal allergy symptoms.

Skin

Skin reactions are another common sign of allergies. These include eczema (also called atopic dermatitis), hives, and contact dermatitis. Contact dermatitis can appear after your skin touches certain jewellery, cosmetics, clothing, or workplace chemicals.

Digestive System

Food allergies can cause stomach cramps, vomiting, and diarrhoea. Symptoms usually appear within minutes to a few hours after eating the trigger food. In severe cases, a food allergy can cause anaphylaxis — a life-threatening emergency.

Common Allergens in Canada

Many everyday substances can trigger allergies. Knowing your triggers is the first step toward managing your symptoms. Here are the most common allergens that affect Canadians.

• Pollen: From trees, grasses, and weeds. A leading cause of seasonal allergic rhinitis across Canada.
• Pet dander: Tiny flakes of skin from cats, dogs, and other animals. A major trigger for asthma in children.
• Dust mites: Microscopic creatures found in bedding, carpets, and upholstered furniture. They thrive in humid environments.
• Mould: Found indoors and outdoors, especially in damp areas like basements and bathrooms.
• Insect stings: Bee and wasp stings can cause serious allergic reactions in some people.
• Foods: Common food allergens include fish, shellfish, peanuts, tree nuts, cow’s milk, eggs, wheat, and soy. These are among Canada’s priority food allergens as listed by Health Canada.
• Medications: Penicillin and other antibiotics, as well as anti-inflammatory drugs like aspirin, can trigger allergic reactions.

How Allergies Are Diagnosed

If you think you have allergies, your family doctor is the best place to start. A proper diagnosis helps you avoid the wrong triggers and choose the right treatment. Diagnosis usually involves a few steps.

Medical History

Your doctor will ask about your symptoms, when they occur, and what seems to trigger them. They will also ask about your personal and family health history. This information helps guide which tests are most useful.

Skin Prick Test

This is one of the most common allergy tests. A small amount of allergen is placed on your forearm or back, and the skin is lightly pricked. If you are allergic, a small raised bump (called a wheal) appears within 15 to 20 minutes. This test is quick, reliable, and widely available in Canada through allergists and some family medicine clinics.

Blood Tests

Blood tests measure levels of a specific antibody called immunoglobulin E (IgE). Your immune system produces IgE in response to allergens. High IgE levels for a specific substance suggest an allergy to that substance. Common blood tests include the RAST (Radio Allergo Sorbent Test) and the PRIST (Paper Radio Immuno Sorbent Test).

Nasal and Food Challenge Tests

In some cases, a doctor may expose you to a suspected allergen in a controlled setting to watch for a reaction. Food challenge tests involve eating a small, carefully measured amount of a suspected food allergen under medical supervision. These tests are done in a clinical setting where emergency treatment is available if needed. Never try a food challenge test at home.

Allergy Tests for Children

Younger children may need different testing approaches. The Phadiatop Infant test is designed for children between the ages of zero and four. It screens for common food and airborne allergens. Older children and adults can use the standard Phadiatop test, which checks for IgE antibodies related to the most common environmental allergens.

Allergy Treatment Options

The good news is that most allergies are manageable. Treatment depends on the type and severity of your allergies. In Canada, you have access to a range of options — from over-the-counter medications to specialist-guided immunotherapy.

Medications

For mild to moderate allergy symptoms, several types of medication can help:

• Antihistamines: These block the chemicals that cause allergy symptoms. They are available over the counter at most Canadian pharmacies and work well for hay fever, hives, and itchy eyes.
• Corticosteroids (cortisone-based): Available as nasal sprays, creams, or pills. They reduce inflammation and are very effective for allergic rhinitis and skin reactions. Some forms are prescription-only.
• Nasal decongestants: These help relieve nasal congestion in the short term. However, they should not be used for more than three days without speaking to a pharmacist or doctor.
• Antibiotics: Sometimes prescribed if an allergic reaction leads to a secondary infection, such as a sinus infection.

Immunotherapy (Allergy Shots)

Immunotherapy — also called allergy shots or allergy vaccines — is a long-term treatment that can reduce your sensitivity to allergens. A small amount of the allergen is injected regularly over several months or years. Over time, your immune system becomes less reactive. This treatment is overseen by a specialist in allergy and immunology. Mayo Clinic provides a helpful overview of allergy immunotherapy options.

Complementary and Natural Approaches

Some people find relief using complementary therapies alongside conventional treatment. These include acupuncture and homeopathy. Certain herbal teas — such as nettle leaf, dandelion, and blackcurrant leaf — have traditional use for allergy relief. However, the scientific evidence for most natural remedies is limited. Always speak with your doctor or pharmacist before trying herbal supplements, especially if you take other medications.

When to See a Doctor

If your allergy symptoms are affecting your quality of life, it is time to speak to a healthcare provider. Do not wait for symptoms to become severe. Acting early makes treatment more effective.

Your family doctor is the best first point of contact for allergy concerns in Canada. They can assess your symptoms, order tests, and refer you to an allergist or immunologist if needed. Most provincial health plans cover allergy testing and specialist referrals when ordered by a family doctor.

If you do not have a family doctor, a walk-in clinic can help with initial assessment and treatment. Walk-in clinics are available across most Canadian cities and towns. Some provinces also offer telehealth services where you can speak to a nurse or doctor by phone or video at no cost.

Seek emergency care immediately if you experience signs of anaphylaxis. These include difficulty breathing, swelling of the throat, a sudden drop in blood pressure, or loss of consciousness. Anaphylaxis is a medical emergency. Call 911 right away. If you have a history of severe allergic reactions, your doctor may prescribe an epinephrine auto-injector (such as an EpiPen) to carry with you at all times.

Frequently Asked Questions About Allergies

Key Takeaways

• Allergies affect about 20% of Canadians and can involve the nose, eyes, lungs, skin, and digestive system.
• Common allergens include pollen, pet dander, dust mites, mould, insect stings, certain foods, and medications.
• Your immune system produces IgE antibodies that overreact to allergens, causing allergy symptoms.
• Diagnosis involves medical history, skin prick tests, and blood tests. Your family doctor or allergist can guide this process.
• Treatment options include antihistamines, corticosteroids, decongestants, and immunotherapy (allergy shots).
• Most allergy care is covered under provincial health plans when referred through a family doctor.
• Anaphylaxis is a medical emergency — call 911 immediately and use an EpiPen if prescribed.
• Always consult your family doctor, walk-in clinic, or a licensed healthcare provider before starting any new treatment for allergies. This article is for informational purposes only and is not a substitute for professional medical advice.