[Delayed-type allergy for heparin and fractions of low-molecular-weight heparin]

A patient is described with proven delayed type allergy for heparin and a low molecular heparin. A literature survey shows that the dermatological picture varies. Occurrence of erythematous plaques without a superficial dermatitis is possible. Epicutaneous tests are often not sufficient, and intracutaneous or even subcutaneous tests are necessary to demonstrate the allergy.