Necrosis of skin induced by coumarin in a patient deficient in protein S

Abstract

In the initial phase of oral anticoagulation the concentration of protein C falls more rapidly than that of the other vitamin K dependent factors (except facor VII), resulting in a transient hypercoagulable state. This is more pronounced in patients deficient in protein C and is probably responsible for the development of thrombi in the microvasculature of the skin. We report a case of skin necrosis induced by coumarin in a patient with functional deficiency of protein S and normal concentrations of protein C.