Sensitization to storage mites in house dust mite (Dermatophagoides pteronyssinus) allergic patients. Comparison of a rural and an urban population.

In this study, sera collected from 50 patients (24 females, 26 males) with Type I allergy to house dust mite (Dermatophagoides pteronyssinus) were investigated for IgE antibodies specific for eight different mite species including storage mites of the families Pyroglyphidae, Glycyphagidae and Acaridae. According to their environment the patients were divided into two groups. Group I consisted of 24 (11 women, 13 men) farmers working and living in rural regions of Austria (Styria, Lower Austria), group II included 26 citizens of Vienna (13 women, 13 men). As expected, RAST investigations revealed a higher rate of sensitization to storage mites in the farmer group. Comparing the two patient groups, sensitization to Lepidoglyphus destructor and Tyrophagus putreus was markedly increased in the farmer group. However, the sensitization rate to storage mites was also considerably high in city dwellers. Elevated levels of IgE specific for Euroglyphus maynei were more frequently observed in the urban collective. RAST-inhibition experiments suggest a partial crossreactivity between house dust mites and storage mites. In their living environment, patients with perennial Type I allergy are exposed to multiple different mite-derived allergens in addition to the well-known house dust mite allergens. These allergens lead to sensitization and are therefore of clinical importance.