Discussion

Heparin-induced IgE-mediated hypersensitivity and anaphylactoid reactions, although rare, can pose a serious clinical problem for patients requiring cardiopulmonary bypass. 3 Standardized skin tests with heparin components are not available to investigate for IgE-mediated heparin allergy, nor are they as reliable as standard penicillin skin tests with major and minor determinant components of the penicillin molecule. Typically, the most commonly encountered adverse reactions to heparin are hemorrhage, delayed hypersensitivity reactions, and heparin-induced thrombocytopenia (HIT). HIT is an autoimmune-