The objective of this study was to perform nasal provocation tests with standardized extracts of Dermatophagoides pteronyssinus, D. farinae, Lepidoglyphus destructor and Tyrophagus putrescentiae in a group of patients sensitized to Dermatophagoides spp.

A total of 25 patients with allergic rhinitis with or without asthma were entered in the study. All patients had positive skin tests to Dermatophagoides spp. Three groups of patients were studied. Group A consisted of 10 patients, who underwent nasal provocation tests with standardized extracts of D. pteronyssinus and D. farinae (100 HEP/ml). Group B consisted of 10 patients, 9 of whom were skin prick test positive to L. destructor. All 10 patients underwent a nasal provocation test with L. destructor and 5 with D. pteronyssinus. Group C, consisted of 5 patients, 2 of whom were skin test positive to T. putrescentiae. All individuals underwent nasal provocation tests with T. putrescentiae and Dermatophagoides spp. Specific IgE was measured by the CAP system.

Group A: 7 patients had a positive provocation test with D. pteronyssinus and 8 with D. farinae. Group B: 6 patients had a positive provocation test with L. destructor. Group C: 3 patients had a positive provocation test with T. putrescentiae.

We confirm a high prevalence of positive nasal challenges to L. destructor and T. putrescentiae in patients sensitized to these mites and to Dermatophagoides spp. The clinical relevance of these mites species is suggested. In general, there was a good correlation between specific IgE levels and positive provocation tests.