[Allergy to dust mites].

House dust mites are the most important indoor allergens in our region. During recent years more dwellings have become infested, most likely as a result of increased indoor humidity due to reduced ventilation. Among Danish adults, 14% have developed IgE against mites. The allergens are stable and can remain for years. Keeping the humidity low (< 45%) during winter months is the most important limiting factor for mite growth. It can be accomplished by ventilation and heating. If bedding, pillow, eiderdown and covering mattress are washedat temperatures > 55 degrees C mites are killed and allergens removed. In addition mattress covers seem to be useful, although guidelines for quality assessment are lacking. Reduction in mite exposure will reduce development of allergy in all age groups especially in the newborn period. Immunotherapy can be offered in rhinitis and moderate asthma when sufficient allergen reduction cannot be accomplished.