Epidemiologic aspects of epidermodysplasia verruciformis (L-L 1922) in Japan.

A survey of epidermodysplasia verruciformis (EV), a skin disease caused by human papillomavirus (HPV), was made by means of a questionnaire sent to 92 university hospitals. Replies were obtained from 68 hospitals (74% recovery) reporting 66 patients. Fewer patients were reported from north-eastern Japan than from south-western Japan. Many EV patients were from families of consanguineous marriages (44%), showing a high incidence of intra-familial onset after consanguineous marriages. The complication of malignant tumors was observed in 36 of 62 cases (58%). Malignant tumors of the skin developed at an early age in EV patients. These cancers developed predominantly in exposed areas of the skin (72%). The time from onset of skin lesions to the onset of cancer seemed to be related to the nature of the lesions in EV patients. These findings suggest that the interaction of HPVs, ultraviolet rays and host factors is associated with the development of skin carcinomas.