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Delayed-onset heparin-induced thrombocytopenia

Maureen A Smythe1, Jennifer L Stephens, Joan C Mattson

  • 1Department of Pharmacy Practice, Wayne State University, William Beaumont Hospital, Royal Oak, MI 48201, USA. msmythe@beaumont.edu

Annals of Emergency Medicine
|March 30, 2005
PubMed

Delayed-onset heparin-induced thrombocytopenia is a syndrome in which thrombocytopenia and thrombosis begin several days after heparin discontinuation. Delayed-onset heparin-induced thrombocytopenia is caused by immunoglobulin G antibodies that are reactive against the heparin-platelet factor 4 complex in the absence of circulating heparin. We describe 2 patients with delayed-onset heparin-induced thrombocytopenia who presented to the emergency department. An 88-year-old man and a 62-year-old man experienced thrombocytopenia and thrombosis 9 or more days after heparin cessation and demonstrated a further decrease in platelet count on reexposure to heparin. Delayed-onset heparin-induced thrombocytopenia should be included in the differential diagnosis of a patient with recent heparin exposure who presents with thrombosis or thrombocytopenia.

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