Papular acrodermatitis of childhood (Gianotti-Crosti disease).

An 11-year-old boy had lentil-sized lichenoid papules, localized to the limbs and trunk, together with acute, nonicteric, hepatitis B surface antigen-positive hepatitis. The clinical picture and course were typical of Gianotti-Crosti disease. Monoclonal antibodies were used to study the lymphocyte subpopulations and surface antigens in the inflammatory infiltrate in frozen sections of a skin biopsy specimen. The results provide data on the pathogenic mechanism of the papular exanthem.