[Cutaneous reactions to heparin: immunological and clinical aspects]

Skin reactions to heparin are rare, the most frequent manifestation being skin necrosis. Reactions occur either as an isolated manifestation or within a context of heparin-induced thrombopenia. Urticarious and eczematous reaction, either localized at injection sites or with a general distribution, have been recently reported. In all cases, it is mandatory to withdraw heparin therapy. Such accidents can be observed with all types of heparin (standard heparin and low-molecular weight heparin). Cross-reactions between two types of heparin are frequent. Skin tests can be used to guide heparintherapy.