A case of lichenoid purpura possibly caused by diltiazem hydrochloride

A 65-year-old Japanese man presented with itchy purpuric lichenoid papules of six months' duration on his legs and buttock. A topical glucocorticoid ointment was not effective. The biopsy specimen histologically showed a dense lichenoid infiltration of lymphocytes and histiocytes into the dermoepidermal junction; red blood cells were seen in the infiltration. Based on the clinical and pathological findings, we diagnosed this case as lichenoid purpura of Gougerot-Blum. The lesions disappeared when the diltiazem hydrochloride that he had been taking was discontinued.