Perforating folliculitis in association with primary sclerosing cholangitis.

Two patients with primary sclerosing cholangitis developed perforating lesions in the skin of the extremities. Clinically and histologically, the cutaneous condition showed the features of perforating folliculitis with superimposed lesions of prurigo nodularis. The course of the eruption paralleled the severity of the biliary disease. A theory of pathogenesis for the development of the perforating folliculitis in these patients is suggested. To the best of our knowledge, this is the first report of the coexistence of both conditions.