Warfarin induced dermatitis and venous thrombosis in a patient with Protein S deficiency.

A case of warfarin-induced dermatitis in a 79 year-old patient with Protein S deficiency is described. Both total Protein S antigen and free Protein S were moderately reduced (about 50%). The skin lesion did not progress to frank necrosis and it was associated with elevated creatin phosphokinase (CPK) levels in plasma and with thrombosis of the anterior tibial vein localized to the area of dermatitis (probably warfarin-induced deep venous thrombosis). After warfarin withdrawal and beginning of heparin therapy, serum CPK rapidly normalized and the skin lesion improved.