RESUMO
"Purple toe" syndrome is an extremely rare complication of warfarin therapy. The occurrence of purple toe syndrome is characterized by a sudden appearance of purplish discoloration of toes and the sides of feet. The skin lesions usually develop 3-8 weeks after beginning anticoagulation. The pathogenesis was not clearly defined but the presence of atherosclerosis in most of patients led to suggest that the mechanism was related to cholesterol emboli from the atherosclerotic plaques and warfarin- induced bleeding into the plaques. These microemboli are commonly associated with irreversible organ dysfunction such as renal failure, distal gangrene, pancreatitis, and multifocal myocardial necrosis. Therefore purple toe syndrome may be considered as a sentinel of cholesterol crystal embolism. Once established, anticoagulation and thrombolysis are contraindicated. Necrosis and gangrenous changes may result in loss of limb and occasional mortality has been reported. We report a case of purple toe syndrome associated with acute renal failure after warfarin therapy with a review of literatures.