Drug eruptions with lichenoid histology produced by captopril.

Three cases are presented with a rash due to captopril which, on histology, showed a lichenoid pattern of bandlike upper dermal infiltrate of lymphocytes and histiocytes, together with hydropic degeneration of the basal layer of the epidermis producing Civatte bodies and pigmentary incontinence. The rash presented either as a pityriasis rosea-like picture which appeared about three to six months after the onset of treatment in patients taking low doses, or alternatively, as lichenoid plaques which appeared three to six months after commencement of medication in patients taking high doses. Although both clinical patterns produced a "saw tooth" pattern of the epidermal rete ridges, hypergranulosis and acanthosis were seen only with the lichenoid plaques.