[Pityriasis lichenoides (author's transl)].

A review of the literature concerning the pityriasis lichenoides and the study of 34 personal cases show that three main clinical patterns are found in pityriasis lichenoides: maculo-papular, leukomelanodermal, necrotic. The course is very variable: rarely seven weeks, more often seven months and sometimes seven years. The disease is issued from an angiitis including a mostly lymphocytic infiltration. The epidermis is secondarily invaded by inflammatory cells and shows focal parakeratosis. There is no specific immunologic disorder: immunohistopathologic study is generally normal (rarely IgM or C3 deposits); no circulating immune complex is found. Some patients improved with dapsone or photochemotherapy.