Heterogeneous distribution of mast cells in lichenified lesions of atopic dermatitis.

The aim of the present study was to determine whether the number of mast cells in lichenified lesions of atopic dermatitis (AD) have a relationship to familial background of atopic respiratory disease (ARD). We obtained biopsy specimens of lichenified lesions from 59 consecutive patients with AD. They included 35 AD patients who had a personal history of ARD, 9 AD patients without a personal history of ARD but with a family history of ARD, and 15 "pure" AD patients without a personal or a family history of ARD. From each biopsy specimen, 4 microns-thick paraffin-embedded sections and/or 1 micron-thick Epon-embedded sections were prepared, and stained with Giemsa's reagent. With both methods of preparation, the sections from AD patients with a personal history of ARD showed significantly greater mast cell number in lichenified lesions than the "pure" AD patients. It is suggested that the increase of mast cells often seen in AD lesions may be characteristic of a subgroup of AD patients who have a predisposition for ARD.