Sensitization to the domestic mites Blomia tropicalis, Chortoglyphus arcuatus, Lepidoglyphus destructor and Aleuroglyphus ovatus was investigated in 77 subjects with clinical symptoms of asthma and/or allergic rhinitis and a positive skin prick test (wheal > or = 3 mm) to Dermatophagoides pteronyssinus and/or D. farinae. Seventy patients were skin test-positive to D. pteronyssinus and 73 to D. farinae. Serum samples from 29 nonallergic, skin test-negative individuals were used as negative controls. Specific IgE was determined by RAST and the results expressed as the % of the total counts bound (% TCB). A positive result (> or = 1% TCB) to D. farinae was detected in 89.6% of subjects, to B. tropicalis in 80.5%, to D. pteronyssinus in 75.3%, to C. arcuatus in 71.4%, to A. ovatus in 68.8% and to L. destructor in 59.7%. None of the controls had a positive RAST to any of the mite species. Different IgE binding patterns were observed among these subjects, suggesting sensitization to unique as well as common allergens in the different mite species. Sensitization to Pyroglyphidae (D. pteronyssinus and D. farinae) and non-Pyroglyphidae mites (B. tropicalis, C. arcuatus, L. destructor and A. ovatus) is common among allergic individuals in Cartagena. Extracts of these mites may be needed for a more accurate diagnosis and effective treatment of respiratory diseases due to mite allergy in tropical environments.