Overview
Dust mite allergy, also known as house dust mite allergy, is a common IgE-mediated allergic condition caused by exposure to microscopic mites that live in household textiles such as bedding, mattresses, carpets, curtains, and upholstered furniture.
Dust mites thrive in warm and humid indoor environments and feed on shed human skin cells. The most common species responsible for allergy are Dermatophagoides pteronyssinus and Dermatophagoides farinae. Proteins present in mite body parts and fecal particles act as potent allergens. Repeated exposure leads to sensitization and Type I hypersensitivity reactions, making dust mite allergy a major cause of perennial allergic rhinitis, asthma, and chronic allergic symptoms
Symptoms
Symptoms of dust mite allergy mainly affect the respiratory tract, eyes, skin, and sleep patterns. Nasal symptoms include sneezing, nasal congestion, runny nose, nasal itching, and postnasal drip. Eye involvement presents as itchy, red, watery, and puffy eyes due to allergic conjunctivitis.
Respiratory symptoms may include coughing, wheezing, shortness of breath, chest tightness, and nocturnal cough, especially in individuals with asthma. Skin manifestations include itching, redness, dryness, scaling, eczema, and flare-ups of atopic dermatitis following exposure. Sleep-related symptoms such as disturbed sleep, snoring, nighttime coughing, daytime fatigue, headache, irritability, and reduced concentration are also commonly reported.
Causes
Dust mite allergy is caused by inhalation or contact with mite allergens present in household dust. Upon exposure, allergens penetrate the epithelial barrier and are recognized by the immune system. Sensitized individuals produce allergen-specific IgE antibodies, which bind to mast cells and basophils.
Re-exposure leads to mast cell degranulation and release of histamine and inflammatory mediators, resulting in early-phase allergic reactions. Late-phase reactions occur hours later due to the recruitment of eosinophils and other inflammatory cells, causing persistent inflammation. Chronic exposure leads to epithelial damage, airway remodeling, and long-term allergic disease progression.
Risk Factors
Risk factors for dust mite allergy include a family history of allergy, asthma, or atopic conditions. Genetic predisposition involving immune regulation increases susceptibility. Environmental factors such as high indoor humidity, warm climates, poor ventilation, and accumulation of dust in carpets, bedding, and upholstery promote mite growth.
Early-life exposure to indoor allergens increases the likelihood of sensitization. Personal risk factors include existing asthma, allergic rhinitis, eczema, or an immune imbalance with Th2 dominance. Lifestyle factors such as infrequent cleaning, use of non-washable bedding, old mattresses, and the presence of pets further increase allergen exposure.
Prevention
Prevention of dust mite allergy focuses on reducing allergen exposure in the indoor environment. Using allergen-proof covers for mattresses, pillows, and blankets helps block mite allergens. Washing bedding weekly in hot water at high temperatures effectively reduces mite load. Maintaining indoor humidity below fifty percent using dehumidifiers or air conditioning limits mite survival.
Regular vacuuming with HEPA-filter vacuum cleaners and removal of carpets, heavy curtains, and stuffed toys reduces dust accumulation. Airing bedding in sunlight and maintaining cool indoor temperatures further inhibit mite growth. Environmental control combined with medical management helps reduce symptoms and prevent disease progression.
