Coexistent lepromatous leprosy and reactive perforating collagenosis.

The cases of two young men with coexistent lepromatous leprosy and reactive perforating collagenosis are reported. Although both patients' parents were consanguineous, experimental induction of Koebner's phenomenon by superficial scratching failed to produce the lesions of reactive perforating collagenosis. The lesions of reactive perforating collagenosis showed a satisfactory response to treatment with topical retinoic acid.