Delayed hypersensitivity to one low-molecular-weight heparin with tolerance of other low-molecular-weight heparins.

We report a patient who developed infiltrated plaques at the sites of subcutaneous injection of a low-molecular-weight heparin. Skin tests and a lymphocyte transformation test revealed hypersensitivity to sandoparin and heparin sodium. The low-molecular-weight heparins nadroparin and dalteparin were subsequently tolerated without adverse effects. Possible risk factors for sensitization are discussed.