Aeroallergen

An aeroallergen is any airborne substance capable of triggering an allergic reaction in susceptible individuals. These substances are typically inhaled and may provoke IgE-mediated responses that affect the nose, eyes, and respiratory tract.

Common aeroallergens include pollen from trees, grasses, and weeds; mold spores; animal dander from pets such as cats and dogs; dust mite feces and body fragments; cockroach allergens; and various occupational allergens such as enzymes, latex, or animal-derived materials. The prevalence and seasonal pattern of aeroallergens vary by geography, climate, and indoor environments.

In sensitized individuals, contact with an aeroallergen leads to the production of allergen-specific IgE antibodies. Re-exposure causes cross-linking of IgE on mast cells and basophils, releasing mediators like histamine and leukotrienes. This results in symptoms such as sneezing, nasal congestion, rhinorrhea, itchy eyes, coughing, wheeze, and shortness of breath. Allergic rhinitis and allergic asthma are common clinical manifestations.

Diagnosis relies on clinical history and objective testing. Skin prick testing or serum-specific IgE testing helps identify sensitization to particular aeroallergens. Nasal or bronchial challenges may be used in certain cases.

Management focuses on avoidance of known aeroallergens, pharmacotherapy, and sometimes allergen immunotherapy. Treatments include antihistamines, intranasal corticosteroids, decongestants, leukotriene receptor antagonists, and inhaled corticosteroids for asthma. Allergen immunotherapy, delivered subcutaneously or sublingually, can modify the long-term course of sensitization and symptoms. Public health measures address indoor air quality and climate-related changes in aeroallergen exposure.