Langerhans cell histiocytosis (LCH) is a rare disease of Langerhans cell proliferation, has a broad spectrum of clinical symptoms, course and prognosis. We report the case of a 41-year-old man with LCH who exhibited dark red nodules on the trunk. The patient also exhibited swelling of the cervical lymph nodes and bilateral lung and skull lesions in X-ray examination. As there were no signs of severe physical symptoms or organ failure, we prescribed a course of oral treatment only (PSL 30mg/day for 7 weeks) and prohibited smoking. After treatment, the skin lesions disappeared. In this report, we present a case of the typical LCH case and in addition, examined the statistical relationship between clinical cutaneous symptoms and prognosis of 66 adult LCH cases reported from 1993 to 1998 in Japan. In result, cutaneous lesions in adult LCH are relatively common, mostly present as papules or nodules. Not infrequently, there are petechiae or purpuric lesions, which are considered as poor signs, and a rapid enlargement of cutaneous lesions is also. Lahey score is almost correlate with prognosis of adult LCH. These factors may be useful way to determine a prognosis of adult LCH.
