European House Dust Mite

• GeneralIt measures 0.3 mm and feeds on flakes of skin; its droppings are the main cause of household respiratory allergy.
• It depends entirely on ambient humidity: it absorbs water from the air and dies if relative humidity stays low, which is why it is all but absent in dry climates or at high altitude.
• It neither bites nor parasitises anyone: the problem is the proteins in its droppings and in the remains of its body.
• It is the most widespread source of indoor allergens in the world: between 1 and 2% of the population has an allergic reaction in its presence.
• Its allergens are a leading cause of asthma, allergic rhinitis and atopic dermatitis.
• The two main ones, called Der p 1 and Der p 2, account for 50 to 60% of the reactivity in sensitised people.
• Der p 1 is a protease: it breaks down the barrier of the respiratory epithelium and activates immune cells, which explains how so tiny an animal causes so much.
• Analysis of its proteome predicted 12,530 proteins and confirmed the expression of 4,002.
• It is genetically closer to Euroglyphus maynei than to the other common house dust species, Dermatophagoides farinae.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Mattresses, carpets, sofas and household textiles

Sources consulted: Wikipedia (es): Dermatophagoides pteronyssinus · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid