Familial background of respiratory atopy. A factor of type I allergy to house dust mite in patients with atopic dermatitis.

Skin prick and radioallergosorbent tests with the house dust mite were performed in 120 patients with atopic dermatitis. The results showed that about 60% of the patients had type I allergy to the mite. Results of the prick and radioallergosorbent tests did not relate to the severity of skin involvement, nor to the seasonal fluctuation of the disease. Positive skin and radioallergosorbent tests occurred in many patients with atopic dermatitis who had a personal or family history of respiratory atopy. However, both of these tests were negative in the majority of patients with "pure" atopic dermatitis who had neither a personal nor a family history of respiratory atopy. It was suggested that a familial background of respiratory atopy is an important factor for the development of type I allergy to the house dust mite in patients with atopic dermatitis.