Perforating lichen nitidus.

A skin biopsy from an 8-year-old boy with generalized lichen nitidus revealed a transepidermal perforating lesion never observed before in this disorder. A disturbance in dermo-epidermal interaction with alterations of epidermal cell kinetics could explain this finding in a disease which, curiously, shows many histologic features conducive to transepidermal perforation. A clear distinction should be made between primary and secondary perforating dermatoses, since perforation per se is a non-specific cutaneous reaction pattern occurring in the course of many unrelated disorders.