Your Body on Seasonal Allergies

The immune system is overworked and underpaid. It’s constantly responsible for scanning the body for precancerous cells, sensing and fighting infection, and regulating inflammation. The immune system must also maintain tolerance to the body’s own cells and tissues, as well as to antigens from food and the environment.

Immune tolerance is the prevention of an immune response against a certain antigen. This is important for maintaining overall balance in the body and preventing autoimmune and allergic reactions. But when it comes to seasonal allergies, tolerance to a normally harmless environmental antigen, such as grass or birch pollen, is lost.

What’s in a name?

Allergic rhinitis is an immune-mediated mucosal inflammatory reaction in the nasal passageways, which may cause symptoms including nasal congestion, runny nose, frequent sneezing, and itchy nose and eyes. Also known as hay fever, allergic rhinitis often co-occurs with asthma and conjunctivitis. Allergic rhinitis may result from both seasonal and perennial allergies.

Seasonal allergens are airborne particles from the environment that, in those who are hypersensitive, trigger allergic rhinitis upon inhalation. Symptoms wax and wane with the season. Common seasonal allergens include pollen from grass, trees (including birch), ragweed, and mold.

Perennial allergens are unrelated to the season and may cause allergic rhinitis in hypersensitive individuals all year long. Common perennial allergen sources include pet dander, house dust mites, and cockroaches. Compared with seasonal allergies, it’s less common for perennial allergies to cause eye symptoms.

Feeling sensitive

Allergic rhinitis is a hypersensitivity reaction, in which the immune system inappropriately and excessively fights back against the antigen as if it were a threat. Specifically, allergic rhinitis is a type I hypersensitivity reaction, in which immunoglobulin E (IgE) antibodies are recruited upon detection of an antigen.

Seasonal allergic rhinitis symptoms can present very quickly after pollen antigen recognition. Type I hypersensitivity reactions happen within 24 hours of antigen exposure.

Under the microscope

As soon as the immune system reacts to an antigen from pollen, IgE then binds to the IgE receptors on mast cells and basophils. This binding causes the mast cells and basophils to degranulate, which releases histamine, leukotrienes, prostaglandins, and other mediators of inflammation into the area.

The problem is that these compounds have no real enemy to battle in the nasal pathways and instead irritate the local tissue. The resulting inflammation causes the telltale symptoms of seasonal allergies: nasal and ear congestion; runny nose; postnasal drip; sneezing; and itchiness of the palate, nose, eyes, and ears.

Contributing factors

There are genetic, epigenetic, socio-economic, and environmental risk factors for seasonal allergic rhinitis.

The “hygiene hypothesis” suggests that a lack of early life exposure to microbes and antigens may impair proper immune function and increase susceptibility to allergic diseases. However, persistent pollen exposure in infancy increases risk of allergic rhinitis.

Geographic distribution affects risk of seasonal allergy. For instance, residents of Kingston, Ontario, have a higher-than-average sensitization rate to Bermuda grass.

Climate change and air pollutants are acknowledged aggravators of allergic rhinitis.

Drinking milk has a protective effect on hay fever risk.

Treatment options

If over-the-counter allergy medications just aren’t cutting it, consider asking for help.

Allergists may offer skin prick testing and other forms of assessment to determine if IgE is active when presented with relevant allergens. Treatment may include an intranasal, oral, or ocular antihistamine or corticosteroid, or a combination of both.

Allergen immunotherapy (“allergy shots”) may be indicated for patients with persistent symptoms. This involves administering a small amount of allergen into the skin or under the tongue to stimulate an allergic response, with the goal of building tolerance over time.

Acupuncturists can provide individualized acupuncture treatments for seasonal allergy sufferers, which may lower nasal inflammation, reduce nasal symptom score, soothe itchy palate, reduce sneezing, and improve quality of life in some individuals. Research supports the safety and efficacy of acupuncture in the treatment of both seasonal and perennial allergic rhinitis.

Naturopaths offer a whole-body approach to testing and treatment. Since IgE-mediated seasonal allergies can present with cross-reactions to food, naturopaths can offer IgE-based food sensitivity testing to investigate pollen food allergy syndrome.

Treatments are individually curated to support the optimal functioning of the immune system, and may involve nutrients, herbs, homeopathic remedies, acupuncture, and lifestyle modifications.