title: [Two surgical case reports showing atypical heparin-induced thrombocytopenia].
abstract: Heparin-induced thrombocytopenia (HIT) represents a serious side effect caused by an atypical immune response to platelet factor 4 leading to platelet activation and thrombin formation. These patients are at high risk of thromboembolism, with a rapid drop in platelet count between days 5 and 14 after the initiation of heparin treatment. In single cases, especially after major surgery, platelet count reduction might be absent or hidden by preceding thrombocytosis. Different clinical manifestations of HIT include unspecific skin reactions with potential necrosis at the site of heparin injection, mostly after the application of unfractionated heparin but also with low molecular weight heparin. In heparin-induced skin necrosis, administration of unfractionated or low molecular weight heparin is contraindicated and heparin therapy should be stopped immediately. Instead, an alternative anticoagulant in the form of a direct thrombin inhibitor such as argatroban, and respectively lepirudin, or danaparoid sodium must be administered. Due to frequent misinterpretations of heparin-induced unspecific skin reactions, especially in the absence of thrombocytopenia, we present two case reports which should increase the awareness of HIT's various clinical pictures.
authors.affiliation: Abteilung für Plastische und Wiederherstellungschirurgie, Klinikum rechts der Isar, Ismaninger Strasse 22, 81675 München. hoehnke@lrz.tum.de
authors.forename: C
authors.initials: C
authors.lastname: Höhnke
authors.forename: S
authors.initials: S
authors.lastname: Haas
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D001120:Arginine / Q000031:analogs & derivatives; D002809:Chondroitin Sulfates / Q000627:therapeutic use; D003871:Dermatan Sulfate / Q000627:therapeutic use; D003875:Drug Eruptions / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects*; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000009:adverse effects; D006497:Heparan Sulfate / Q000627:therapeutic use; D006629:Hirudins; D006801:Humans; D008297:Male; D010875:Pipecolic Acids / Q000627:therapeutic use; D010976:Platelet Count; D010978:Platelet Factor 4 / Q000276:immunology; D011183:Postoperative Complications / Q000517:prevention & control; D011994:Recombinant Proteins / Q000627:therapeutic use; D013449:Sulfonamides; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis / Q000276:immunology; D013927:Thrombosis / Q000517:prevention & control; D013997:Time Factors
chemical_list: D000925:Anticoagulants; D001120:Arginine; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D006493:Heparin; D006495:Heparin, Low-Molecular-Weight; D006497:Heparan Sulfate; D006629:Hirudins; D010875:Pipecolic Acids; D010978:Platelet Factor 4; D011994:Recombinant Proteins; D013449:Sulfonamides; C035838:danaparoid; C031942:argatroban; C083544:lepirudin