title: Warfarin skin necrosis in a postpartum woman with protein S deficiency.
abstract: BACKGROUND
  Warfarin-induced skin necrosis is a rare and dangerous complication affecting 0.01-0.1% of patients on warfarin. Deficiencies in protein C or protein S in association with other factors have been implicated in its etiology. No report has described this disorder in the immediate postpartum period in patients with protein S deficiency.
  
  
  METHODS
  A 1-week postpartum woman with known protein S deficiency presented with skin necrosis after a previously uneventful course of warfarin.
  
  
  CONCLUSIONS
  Reduced levels of free protein S during the antepartum and immediate postpartum periods predispose protein S-deficient women to warfarin skin necrosis. Previously uncomplicated courses of warfarin do not obviate the possibility of skin necrosis with future warfarin administrations. Initiation of low-dose warfarin with heparin can reduce the likelihood of this disorder.
authors.affiliation: Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: A
authors.initials: A
authors.lastname: Cheng
authors.forename: N S
authors.initials: NS
authors.lastname: Scheinfeld
authors.forename: B
authors.initials: B
authors.lastname: McDowell
authors.forename: A A
authors.initials: AA
authors.lastname: Dokras
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D009336:Necrosis; D049590:Postpartum Period; D011247:Pregnancy; D018455:Protein S Deficiency / Q000188:drug therapy*; D012867:Skin / Q000473:pathology; D012871:Skin Diseases / Q000139:chemically induced* / Q000473:pathology; D014859:Warfarin / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin