Delayed hypersensitivity to enoxaparin

A 65-year-old woman experienced immediate itchy erythematous patches at the subcutaneous injection sites of sodium enoxaparin. An erythematous and inf iltrated 40 x 20 mm lesion on the abdominal wall could be observed at the s ite of enoxaparin injection when she was referred to our clinic 48 h after injection. Lesions subsided spontaneously within I week. She had been on th is treatment 1 and 3 years before without any adverse reaction. To clarify the nature of the reaction, epicutaneous tests with sodium enoxaparin, calc ium nadroparin and calcium heparin were performed, all with negative result s. Skin prick test with sodium enoxaparin was also negative. Biopsy of the cutaneous lesion showed spongiotic dermatitis, strongly suggesting a delaye d hypersensitivity mechanism. We report here on a new case of delayed hyper sensitivity to enoxaparin. Being female, overweight and having prolonged ap plication of the drug were suggested risk factors present in our patient. B iopsy was essential for diagnosis. Although type IV hypersensitivity reacti ons to enoxaparin are rare, we should start to suspect this condition in or der not to underdiagnose it.