An unusual case of adult disseminated cutaneous Langerhans cell histiocytosis

Abstract

Langerhans cell histiocytosis (LCH) represents a group of rare histiocytic syndromes characterized by tissue infiltration with dendritic cells. The management of LCH is difficult because these disorders respond inconsistently to immunosuppressive and chemotherapeutic strategies. We describe a refractory and relapsing case of skin and nail limited LCH in a 27-year-old man. He presented with a 7-year history of an erythematous papular eruption of the scalp, ears, face, trunk, axillae, groins, fingernails, feet, and toenails. Diagnosis of LCH was made based on skin histopathology and immunohistochemical staining. 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. In addition, CD1a was positive in most of the infiltrating cells. Extensive investigations failed to detect systemic involvement. The patient's cutaneous eruption did not respond to various therapeutic interventions, including phototherapy with oral psoralen with long-wave UV radiation in the A range (PUVA) and cyclosporine. Marked but temporary clinical improvement was achieved with thalidomide, etoposide with systemic steroid, and total body electron beam radiotherapy. Now the patient is on maintenance therapy with thalidomide and is under acceptable control.