Allergy to storage mites in asthmatic patients and its relation to damp housing conditions.

The relation between allergy to house dust mites and allergy to storage mites was studied in 326 patients with bronchial asthma. A positive RAST to house dust mites was found in 24.5% and to storage mites in 7.4%. There was a close association between a positive RAST to house dust mites and a positive RAST to storage mites, and 91.6% had a positive RAST to both. Only 0.9% with a negative RAST to house dust mites had a positive RAST to storage mites, whereas the frequency was 27.5% in those with a positive RAST to house dust mites. Present occupation with exposure to storage mites was found in 20.8% with a positive RAST to storage mites. A positive RAST to both house dust mites and storage mites was significantly associated with anamnestic indicators of damp housing conditions. The close association between allergy to house dust mites and allergy to storage mites in this study is probably caused by a common environmental factor, i.e. damp housing conditions.