What is a house dust mite? - briefly
House dust mites are microscopic arachnids that inhabit indoor environments, feeding on shed human skin cells and producing allergenic particles. They belong to the family Pyroglyphidae and are a frequent cause of allergic reactions such as asthma and rhinitis.
What is a house dust mite? - in detail
The house dust mite is a microscopic arachnid belonging to the family Pyroglyphidae, most commonly represented by Dermatophagoides pteronyssinus and Dermatophagoides farinae. Adults measure 0.2–0.3 mm, possess eight legs, and lack eyes. Their bodies are covered with a hard exoskeleton that resists desiccation, allowing survival in low‑humidity environments.
Feeding habits focus on organic detritus: shed human skin cells, fungal spores, and textile fibers. Enzymatic digestion breaks down keratin and other proteins, providing nutrients essential for growth. Reproduction occurs year‑round under favorable conditions (temperature 20–25 °C, relative humidity ≥ 70 %). A female lays 40–100 eggs over her lifespan of 30–40 days; each egg hatches into a larva that undergoes three moulting stages before reaching adulthood.
Typical habitats include bedding, upholstered furniture, carpets, and curtains—areas where human activity supplies abundant food sources. Dust accumulation acts as a reservoir, while microclimatic conditions in these microhabitats maintain the moisture required for survival. Populations can reach several hundred thousand individuals per square meter in heavily infested environments.
Health implications arise from allergenic proteins present in mite feces, body fragments, and saliva. Inhalation of these particles can trigger allergic rhinitis, asthma exacerbations, and atopic dermatitis in sensitized individuals. The most potent allergens, designated Der p 1, Der p 2, Der f 1, and Der f 2, provoke IgE‑mediated immune responses.
Control strategies focus on reducing humidity, removing dust reservoirs, and employing acaricidal agents. Effective measures include:
- Maintaining indoor relative humidity below 50 % using dehumidifiers or ventilation.
- Washing bedding weekly at temperatures ≥ 60 °C to kill mites and eliminate allergens.
- Vacuuming with HEPA‑filtered equipment to capture microscopic particles.
- Applying approved acaricides to carpets and upholstered furniture, following manufacturer guidelines.
Regular monitoring through dust sampling and allergen quantification assists in evaluating the efficacy of interventions and adjusting management plans accordingly.