Abstract
Skin necrosis is a rare but serious complication of oral anticoagulant therapy with warfarin. It is caused by extensive thrombosis of postcapillary venules in the subcutaneous fat, most often in individuals with thrombophilia.
Pathogenesis of necrosis is explained by an imbalance of coagulation and anticoagulation factors. The most significant protective effect of warfarin is the inhibition of carboxylation of prothrombin.
However warfarin also inhibits the anticoagulant proteins C and S. The half-time of factor II is 60-72 hours, while the half-time of protein C is 9 hours, so there is a temporary hypercoagulation leading to skin necrosis.
In the case report we present a 60-year-old man after aortic valve replacement. 8 days after the initiation of anticoagulation therapy with warfarin skin necrosis occurred in the lower limbs, which disappeared after switching to treatment of low molecular weight heparin. Hematologic and genetic examinations did not reveal any congenital hypercoagulable state.