[Lichen purpuricus].

A case of lichen purpuricus in a 19-year-old male is reported. The eruption appeared on the left hand 4 years ago, disappeared spontaneously after 2 years and reappeared later. It was characterized by a few asymptomatic, dark-red colored macules and papules, scattered and not confluent in a plaque. No clinical diagnosis could be made. Histopathological examination showed the presence in the upper dermis of a dense cellular infiltrate and of hemosiderin granules. The infiltrate was composed of lymphocytes, histiocytes and numerous extravasated red cells; it had an bandlike arrangement and was generally separated from the epidermis. On this occasion, a review of the literature and a study of the clinical and histopathological features, as well as of the etiopathogenesis of this dermatosis, are made.