[Skin necrosis with vitamin K antagonists: An imbalance between coagulant and anticoagulant factors]. / Nécroses cutanées aux anti-vitamines K : un déséquilibre entre facteurs pro- et anticoagulants.

INTRODUCTION: Skin necrosis with vitamin k antagonists are rare. They affect more frequently middle-aged and obese women, often within 10 days after initiating of treatment. They occur most often in a context of thrombophilia. CASE REPORT: An 18-year-old obese woman was treated with heparin and fluindione for a lower limb deep venous thrombosis. On day 5, the patient presented fever and skin necrosis, which extended rapidly. We identified an activated protein C resistance and a major inflammatory syndrome related to Mycoplasma pneumoniae infection. The outcome was favorable after discontinuation of the fluindione, introduction of heparin and vitamin K, despite amputation of a toe. CONCLUSION: Skin necrosis is due to a transient hypercoagulable state during the initiation of vitamin K antagonist treatment due to an imbalance between pro- and anticoagulant factors. In our case, it was caused by an activated protein C resistance and an inflammatory syndrome.