[Mites: the principal respiratory allergens of house dust]

The Mites are the most frequent of the lung allergens. Three families have a prime importance. The Pyroglyphidae (of which Dermatophagoides pteronyssinus, Dermatophagoides farinae and Euroglyphus maynei are a part), the Acaridae and the Glyciphagidae which comprise the stock acariens responsible for certain occupational asthmas. After the discovery of the role of mites in respiratory allergy numerous studies have specified the ecological conditions favourable to their development (temperature, relative humidity, the nutritional environment) and have emphasised the beneficial role of altitude and the importance of the characteristics of the habitat. Another avenue of research consists in culture of the acariens, to isolate by immunological chemical purification techniques the glycoproteins responsible to their allergic activity, The studies led to the identification of the major allergens most frequently responsible for sensitizing man. Thus for Dermatophagoides pteronyssinus two major allergens have been identified by different teams. Certain common allergens in different species explain the crossed sensitivity which are frequently observed. One of the major allergens of Dermatophagoides pteronyssinus, the allergen P, is contained in faecal particles of the acariens. These particles are identified in the domestic environment and are easily made into a suspension by normal household activities. Current preventative methods are orientated towards the effect of exclusion of the acariens on the respiratory symptomatology. The diminution of the mite numbers, a reduced frequency of crisis after complete eviction of the allergens from the home and diminished bronchial reactivity to pharmacological mediators after very prolonged eviction. The use of acaricides or of fungicides would merit more numerous controlled studies with a view to showing their efficacy on the respiratory symptomatology of sensitive subjects.(ABSTRACT TRUNCATED AT 250 WORDS)