Overview
Allergic rhinitis is an IgE-mediated hypersensitivity disorder that occurs when the immune system reacts abnormally to airborne allergens. In affected individuals, exposure to allergens such as pollen, dust mites, animal dander, or mold leads to the production of immunoglobulin E antibodies.
These antibodies trigger the release of inflammatory mediators, resulting in nasal and upper airway inflammation. Symptoms usually appear within minutes to a few hours after allergen exposure. Allergic rhinitis is also known as hay fever and is commonly associated with asthma and atopic dermatitis. It affects a significant proportion of both adults and children and represents a major cause of chronic nasal symptoms and reduced quality of life
Symptoms
Symptoms of allergic rhinitis can be divided into early and late manifestations. Early symptoms develop rapidly after allergen exposure and include frequent sneezing, nasal itching, runny nose with watery discharge, and nasal congestion. Itching and redness of the eyes with excessive tearing are common, along with irritation of the throat due to postnasal drip. Some individuals experience itching of the palate and ears.
Late symptoms occur hours after exposure and are characterized by persistent nasal blockage due to mucosal swelling. Mucus becomes thicker, and nasal discharge may reduce while congestion worsens. Sneezing becomes less frequent, but inflammation and edema of the nasal mucosa persist. Fatigue, headache, malaise, sinus pressure, and difficulty concentrating are common in chronic cases. Long-standing symptoms may interfere with sleep, daily activities, and overall well-being.
Causes
Allergic rhinitis is caused by immune sensitization to specific allergens present in the environment. Indoor allergens include dust mites, cockroach allergens, pet dander from cats and dogs, and indoor mold spores.
Outdoor allergens such as tree pollen, grass pollen, weed pollen, and outdoor mold spores are common triggers, especially in seasonal allergic rhinitis. Occupational exposure to substances like latex, flour dust, animal proteins, and chemical vapors can also induce allergic rhinitis. Upon exposure, allergen-specific IgE binds to mast cells, leading to histamine release and inflammatory cascades that affect the nasal mucosa. Repeated exposure enhances sensitization and symptom severity.
Risk Factors
Risk factors for allergic rhinitis include a personal or family history of allergic diseases such as asthma, eczema, or allergic conjunctivitis. Genetic predisposition plays a significant role in immune hypersensitivity.
Early-life exposure to allergens in susceptible individuals increases the likelihood of developing allergic rhinitis. Environmental factors such as high pollen levels, indoor dust accumulation, mold growth, air pollution, and tobacco smoke exposure increase risk. Children and individuals living in urban or poorly ventilated environments are more susceptible. Coexisting asthma or atopic dermatitis further increases disease burden and symptom persistence.
Prevention
Prevention of allergic rhinitis focuses on reducing allergen exposure and controlling inflammation. Identifying and avoiding known triggers is the most effective strategy. Keeping windows closed during high pollen seasons and using air conditioning with HEPA filters helps limit allergen entry. Regular washing of bedding in hot water and use of allergen-proof mattress and pillow covers reduce dust mite exposure. Maintaining low indoor humidity prevents mold growth. Keeping pets out of bedrooms and cleaning surfaces with a damp cloth minimizes allergen spread. Saline nasal irrigation helps remove allergens from the nasal passages. Early diagnosis, allergy testing, and appropriate medical management support long-term symptom control and prevention of complications.
