Primary cutaneous Langerhans cell histiocytosis treated with photochemotherapy.

A 23-year-old man with Langerhans cell histiocytosis presented with asymptomatic, purplish, slightly scaly, confluent papules of one year's duration. Histological studies of biopsy specimens revealed a dense infiltrate of histiocytic mononuclear cells beneath the epidermis; these cells reacted strongly with anti-S-100 antibodies. Extensive investigations failed to detect systemic involvement. He was treated with repeated oral 8-methoxypsoralen (8-MOP) plus ultraviolet A (PUVA) therapy three times a week for two months and then once or twice with maintenance phototherapy. The lesions did not recur during the four-month follow-up period.