[Importance of measuring exposure to the principal indoor allergens in allergic asthma].

Domestic allergens, such as mite and cat allergens, are a leading cause of allergic asthma. Allergen exposure is a risk factor for sensitization. Allergens also play a major role in the development of inflammation and non specific bronchial hyperreactivity as well as in the apparition and modulation of symptomatic asthma. The development of new means of detecting allergens (i.e. immunochemical assays including monoclonal antibodies, quantitative and semiquantitative guanine measurements for mite allergens) has made possible to identify allergens sources and reservoirs. The form in which domestic allergens become airborne is important. The group I and II allergens from mites, the major cockroach allergens are carried on large particles (mean size > 10 microns diameter); in contrast, the major cat allergens are airborne on small particles (40% < 5 microns). Guanine, a metabolic excretion product of mites, is used as a marker for mite feces and is correlated with the presence of major allergens from mites. A colorimetric method (Acarex-TestR) provides a simple and inexpensive method of assaying indoor mite allergen exposure for both doctor and patient alike. By using Acarex-TestR it is possible to evaluate the mite allergen exposure for a population in a particular country. The detection of allergens sources and reservoirs, the quantification of domestic allergens has enabled the evaluation of the effect of a reduction in allergen exposure to be better assessed. Recognition of the risks, environmental control and reduction in allergen loads, should be among the objectives of asthma management.