Mite fauna in the home and sensitivity to house-dust and storage mites

In search of potential new indoor allergen sources, all mites in dust from homes of 55 asthmatic children living in three climatic regions in Sweden w ere counted and identified by light microscope. Antibodies of the IgE class against three house-dust mites and three storage mites were measured in co rresponding serum samples. Mites were found in all but two homes from the n orthernmost area, where levels also were lower than in the other regions. T he highest mite densities were most often found in bedrooms (50%) and livin g rooms (40%). Mite density was increased in homes with high humidity and w as higher in bungalows than in flats. House-dust mites predominated in the south and storage mites in the east central area, particularly in kitchens and bathrooms. Mite-density and IgE-antibody levels against house-dust mite s were significantly associated. The same association applied to storage mi tes. Other species numbered around 100 mites/g dust in some homes. Microsco py helps to identify potentially important mites. Analysing home dust only for house-dust mites will underestimate mite exposure. Storage mites may be as relevant to sensitivity as house-dust mites. As other species occasiona lly were found in high numbers, their relevance should also be assessed.