Respiratory atopy and domestic mite sensitization in Rio de Janeiro

RESUMO

Domestic mites occur in a significant percentage of homens in Rio de Janeiro, a tropical geographic region of Brazil. Local weather conditions (hot and humid) promote the significant mite proliferation. Objective. We are registering the allergic mite sensitization of a population with asthma and/or rhinitis living in this coastal area. Methods. A total of 600 patients with asthma and/or rhinitis aged>=2 years underwent 3,810 allergy skin tests (Multi-Test). Eight different extracts were applied American house dust (Ahd), Brazilian house dust (Bhd), Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), Blomia tropicalis (Bt), Chortoglyhphus arcuatus (Ca), Aleuroglyphus ovatus (Ao) and Lepidoglyphus destructor (Ld). RAST to Dp, Bt, Ca, Ao and Ld were performed with sera of randomized 14 atopic subjects. Results A positive immediate skin test to at least one allergen was detected in 387 patients (64,5 percent). Domestic mite sensitization was documented in about 90 percent of the atopic individuals. Bt has unique antigens since 4.15 percent of the subjects had positive exclusive reactions. RAST analyses showed that both Dp and Bt are the most important local mite sensitizers with cross-reactivity to the other mites. Conclusion. This study confirms that domestic mites are the most prevalent local allergens associated with asthma and/or rhinitis. Sensitization to Bt was very common and it should be checked routinely for the diagnosis of respiratory atopy in Rio de Janeiro