[The clinical course of coumarin-induced necrosis]

In three patients painful reddening of a well-circumscribed area of the skin occurred within five days of starting anticoagulant treatment with phenprocoumon (Marcumar), and within a short time it developed into a full-blown picture of coumarin necrosis. The indication for phenprocoumon was, in the first patient (a 29-year-old mother lying-in after her second child had been born) an increased platelet count and the presence of high risk factors for thromboembolism. In the second patient (25-year-old man) and the third one (45-year-old woman) it was secondary prophylaxis after pulmonary embolus and deep-vein thrombosis, respectively. All three patients were very obese and had a drug allergy, as well as other allergies (bronchial asthma in Cases 1 and 2; allergic rhinitis in Case 3). Phenprocoumon was at once discontinued in all three patients and low-dose heparin administration (Cases 1 and 3) or dextran infusion (Case 2: heparin intolerance) started. All three needed excision of the necrotic tissue with grafting to the skin defect. The coexistence of obesity and allergic diathesis may thus present an especially high risk for coumarin necrosis.