The aim of the present study was to evaluate the efficacy of an oral specific hyposensitization therapy in children with atopic dermatitis and positive prick skin tests and/or RAST to Dermatophagoides pteronyssinus (D.pt.). A total of 60 patients, in three different clinical groups, were selected for a three years clinical trial. Group A: children with atopic dermatitis and allergic asthma and/or rhinitis; groups B and C: children with exclusively atopic dermatitis. Groups A and B received specific hyposensitization therapy. Group C was the control group. The clinical evaluation of the dermatological lesions, at the end of our study, didn't show any significant difference among the three groups. Moreover, the onset of respiratory symptoms between the two groups with exclusively atopic dermatitis was similar and not related to the positivity of prick skin tests and/or RAST to seasonal allergens. Our study suggests that specific hyposensitisation therapy with extracts of D.pt., although with no side effects, does not affect the natural history of atopic dermatitis.