Heparin-associated hematomas: possible allergic reaction

Heparin hypersensitivity is a rare complication of anticoagulation therapy. Our case involved a 34-year-old black male who demonstrated a hypersensitivity to porcine heparin that manifested as bilateral hematomas with ecchymoses from intravascular access sites. When bovine heparin was substituted, there was no evidence of a similar reaction. However, the patient required five times the usual dose to be adequately anticoagulated (partial thromboplastin time 1 1/2-2 times normal value) and eventually developed generalized pruritus.