Abstract
A 75-year-old woman was diagnosed as lichen planus tropicus on clinical and histological findings and photopatch test. The photopatch test showed phototoxic reaction with chlorpromazine and longwave ultraviolet light. And we have also studied thirteen other patients diagnosed as lichen planus based on clinical and histological findings in our clinic. As a result, we found that the photosensitivity due to exposure to the sun and/or drug was the main factor in the development of many cases. We suggest that the patients with lichen planus, whose lesions are suspected due to photosensitivity, must be diagnosed as lichen planus actinicus rather than lichen planus tropicus.
