Adverse reactions to heparin.

Heparin is a medication that has gained widespread use in clinical medicine as the therapy of choice for acute anticoagulation in the prevention and treatment of thromboembolic disease. Therapy with heparin is associated with many potential adverse side effects. Heparin-induced skin necrosis is an uncommon complication of heparin therapy that is now believed to be a thrombotic complication of heparin-induced thrombocytopenia. The pathogenesis of this disorder is unknown, but it is presumed to be immunologically mediated. The diagnosis is frequently one of exclusion. Significant morbidity and mortality may arise from failure to recognize this adverse reaction.