[Lichen aureus or lichen purpuricus; about 5 cases; ultrastructural study].

Clinical, histological and ultrastructural features in five cases of lichen aureus are descirbed. This rare condition with ages ranging here from 6 to 31 consists of a pigmented papular and purpuric eruption. Unilaterally, trunk or limb may be involved, in a possible systematized distribution. The microscopic picture is characterized by a dense histiocytic and lymphocytic infiltration in the upper part of the dermis; extravasation of erythrocytes and iron pigment in the histiocytes are often noticed. In fine structure most cells of the dermal infiltrate are histiocytes (or macrophages) with numerous worm-like structures and even typical Langerhans granules in three cases; histiocytic cells; histiocytes are frequently seen in apposition to lymphocytes. In all these cases, no sign of histiocytosis X is found. Classification of lichen aureus in the group of idiopathic pigmented purpuric eruption is proposed.