What are Seasonal Allergies?
Seasonal allergies, also known as allergic rhinitis or hay fever, occur in response to environmental allergens during specific times of the year. These allergies result from the immune system’s exaggerated reaction to airborne substances, such as pollen, mold spores, or dust mites. An allergen is any substance that induces an immune response, leading to inflammation and characteristic symptoms. The most prevalent allergens associated with seasonal allergies are tree, grass, and weed pollen, particularly from wind-pollinated plants.
Historically, the term “hay fever” originated from hay-cutting season, but it is now used to describe allergic reactions that typically occur during spring, summer, and fall. While allergies can persist year-round, they tend to be less frequent in winter. However, indoor allergens such as pet dander and mold spores can also trigger symptoms year round.
Seasonal Allergy Symptoms
Symptoms of seasonal allergies can range from mild discomfort to severe reactions. Common symptoms include:
Postnasal drainage
Eustachian tube dysfunction leading to ear congestion
Itching of the ear canals, throat, or sinuses
Allergic conjunctivitis (itchy and watery eyes)
Nasal congestion or rhinorrhea (stuffy or runny nose)
Sneezing paroxysms
Less common, yet more concerning symptoms include:
Dyspnea (shortness of breath)
Persistent cough
Cephalgia (headache)
Wheezing (a sign of airway obstruction, often seen in asthmatic patients)
Causes of Seasonal Allergies
The triggers of seasonal allergies vary with the time of year, correlating with the release of specific allergens. When an individual is exposed to a substance to which they are sensitized, the immune system erroneously identifies it as a harmful invader. This prompts the release of inflammatory mediators such as histamines, leukotrienes, and prostaglandins, which result in the clinical manifestations of allergic rhinitis. The severity of the reaction depends on the immune system’s sensitivity and the amount of allergen exposure.
Typical seasonal triggers include:
Tree pollen, common in early spring
Grass pollen, prevalent in late spring and summer
Mold spores, which can occur indoors and outdoors, particularly in damp environments
Dust mites and pet dander, which persist year-round, though symptoms may worsen during specific seasons
Seasonal Allergies Vs Common Cold
Many people often confuse seasonal allergy symptoms with those of the common cold. See the table below to understand the difference better:
Condition | Symptoms | Onset | Duration |
Common cold | Runny nose with thick or watery yellow discharge; low-grade fever; body aches | 1 to 3 days post exposure to cold virus | 3 to 7 days |
Seasonal allergies | Runny nose with thin discharge; no fever | Immediately post exposure to allergens | As long as the exposure to allergens persist |
Most Common Seasonal Allergens and When They Occur
Risk Factors for Seasonal Allergies
Several factors increase the risk of developing seasonal allergies, including:
A history of asthma or other allergic conditions
Presence of atopic dermatitis or eczema
A family history of asthma or allergies
Living or working in an environment with high allergen exposure (e.g., dust mites, pet dander)
Exposure to irritants such as smoke or strong odors, which can exacerbate symptoms
Complications
If left untreated, seasonal allergies can lead to several complications:
Otitis media: Allergies can increase the risk of middle ear infections, particularly in children.
Sinusitis: Prolonged nasal congestion can lead to inflammation or infection of the sinuses.
Asthma exacerbation: Allergies can worsen asthma symptoms, increasing the likelihood of wheezing, coughing, and shortness of breath.
Sleep disturbances: Persistent symptoms may interfere with sleep, leading to fatigue or malaise.
Reduced quality of life: The chronic nature of symptoms can impair daily functioning and productivity.
Diagnosis
Diagnosing seasonal allergies typically involves a combination of clinical evaluation and diagnostic testing:
Medical history and physical exam: A physician will ask detailed questions regarding the onset, duration, and pattern of symptoms, followed by a physical examination.
Skin testing: Involves pricking the skin with small amounts of potential allergens. If an allergic response occurs, a raised bump or wheal will appear at the site of exposure.
Serologic testing: A blood test measuring IgE antibodies can be used to assess allergic sensitivity. The most common test is ImmunoCAP or RAST (Radioallergosorbent Test).
Allergy Treatment
Treatment for seasonal allergies focuses on managing symptoms and reducing exposure to allergens:
Avoidance: Identifying and minimising exposure to known triggers is a primary preventive strategy.
Pharmacotherapy: Medications such as antihistamines, intranasal corticosteroids, and mast cell stabilisers are used to alleviate symptoms. For more severe cases, oral corticosteroids may be prescribed for short-term use.
Immunotherapy: For patients with persistent or severe allergies, allergen immunotherapy (allergy shots) may be considered. This treatment involves administering increasing doses of allergens over time to desensitise the immune system. Sublingual immunotherapy (SLIT) is another option, particularly for pollen induced allergies.
FAQs
1. What are the main causes of seasonal allergies?
Seasonal allergies occur when the body reacts to airborne allergens such as pollen, grass, or mold, triggering the release of inflammatory mediators like histamine.
2. What are the top 5 allergy symptoms?
Sneezing or rhinorrhea
Sinus tenderness or facial pain
Wheezing or dyspnea
Itchy skin or hives
Swelling around the mouth, lips, or eyes
3. How to manage allergy symptoms?
4. Which deficiency is linked to seasonal allergies?
Vitamin D deficiency has been implicated in immune dysregulation, potentially worsening allergic conditions such as asthma and eczema.
5. What is the best treatment for seasonal allergies?
Pharmacologic therapy with antihistamines, corticosteroids, and decongestants
Immunotherapy for persistent cases