Cutaneous Langerhans cell histiocytosis.

A 5 year old boy presented with papules and nodules on face, chest and upper extremities and seborrhea of scalp for 4 years. Some old healed scars were also present. Lesions were pruritic to begin with but were non-itchy. Examination revealed erythematous plaques and nodules on face and upper limbs. Lesions were more marked on forehead, cheek (Fig. 1) and dorsum of hands. There were contractures of little fingers of the both hands (Fig. 2). Lymphadenopathy and hepatosplenomegaly were absent. Histopathological examination from skin lesions was suggestive of langerhans cell histiocytosis (LCH). Immunohistochemical studies showed positive staining with antibodies to S-100 and CD1a, consistent with the diagnosis of LCH. A complete bone survey, CT cranium and chest, ultrasonography abdomen and bone marrow examination were negative for systemic involvement. The final diagnosis was cutaneous LCH without systemic involvement. After a trial of topical steroids which were ineffective, he was started on oral methotrexate 20 mg/m2 weekly for 6 months. Child had marked improvement with complete resolution of the lesions within 6 weeks. He is in regular follow up and there is no recurrence of lesions.