Aeroallergens

Aeroallergens are substances dispersed in the air that can trigger allergic reactions in sensitized individuals when inhaled. They commonly provoke rhinitis, conjunctivitis, and asthma through IgE-mediated immune responses. Major aeroallergens include pollen from trees, grasses, and weeds; fungal spores; dust mite and animal dander; and certain cockroach allergens. Susceptibility and exposure level determine symptom type and severity, which can range from nasal congestion and sneezing to coughing and wheezing.

Outdoor aeroallergens vary by season and region, with pollen peaks tied to plant flowering. Indoor aeroallergens include dust mites in bedding and upholstery, pet dander, and mold spores from damp spaces. Particle size influences where inhaled material deposits; larger pollen grains tend to affect the upper airways, while smaller spores and some pet or cockroach particles can reach the lower airways. Weather, ventilation, and humidity modulate airborne concentrations.

Diagnosis relies on clinical history and tests such as skin prick testing or serum-specific IgE measurements. Management emphasizes exposure reduction and symptom control. Avoidance measures include monitoring pollen counts, keeping windows closed during high pollen periods, using high-efficiency filters, dehumidifying damp rooms, washing bedding in hot water, and minimizing dust sources. Medications (antihistamines, intranasal corticosteroids, inhaled steroids for asthma) and, for some patients, allergen immunotherapy are used. Public health initiatives track aeroallergen levels to guide prevention.