Purpuric dermatosis due to diltiazem

RATIONALE: Diltiazem is a calcium channel blocker that belongs to the benzothiacepine group. This drug is widely used in the treatment of arterial hypertension. It evoques frequent cutaneous eruptions but purpuric dermatosis are exceptional.METHODS: A 82 year- old woman received treatment with diltiazem. She experienced intense pruritus and a generalized widespread eruption after two months of therapy. The lesions consisted on well circumscribed erythemato- purpuric plaques of varying diameter. Some of them progressed into vesicles with residual pigmentation. Lesions resolved within 15 days after discontinuation of diltiazem and treatment with systemic corticosteroids and antihistamines.RESULTS: A cutaneous biopsy showed extravasated erythrocytes within the papillary dermis, and a perivascular lymphohistioytic infiltrate.Patch test with diltiazem(10% in DMSO) was positive (+++) 48 and 72 hours later. Patch tests in 10 control subjects were negative.CONCLUSIONS: 1. We report an exceptionally case of purpuric dermatosis due to diltiazem. 2. Patch-test was useful to the diagnosis. 3. The positive patch test and the anatomopathology finding support a Type IV hypersensitivity reaction. RATIONALE: Diltiazem is a calcium channel blocker that belongs to the benzothiacepine group. This drug is widely used in the treatment of arterial hypertension. It evoques frequent cutaneous eruptions but purpuric dermatosis are exceptional. METHODS: A 82 year- old woman received treatment with diltiazem. She experienced intense pruritus and a generalized widespread eruption after two months of therapy. The lesions consisted on well circumscribed erythemato- purpuric plaques of varying diameter. Some of them progressed into vesicles with residual pigmentation. Lesions resolved within 15 days after discontinuation of diltiazem and treatment with systemic corticosteroids and antihistamines. RESULTS: A cutaneous biopsy showed extravasated erythrocytes within the papillary dermis, and a perivascular lymphohistioytic infiltrate. Patch test with diltiazem(10% in DMSO) was positive (+++) 48 and 72 hours later. Patch tests in 10 control subjects were negative. CONCLUSIONS: 1. We report an exceptionally case of purpuric dermatosis due to diltiazem. 2. Patch-test was useful to the diagnosis. 3. The positive patch test and the anatomopathology finding support a Type IV hypersensitivity reaction.