Chronic recurrent warfarin-induced skin necrosis in a patient with a mechanical mitral valve: a diagnostic mimic of pyoderma gangrenosum

Warfarin-induced skin necrosis (WISN) is a rare but potentially life-threatening complication of warfarin therapy, often presenting within the first few days of initiation. It is more commonly seen in patients with underlying protein C or S deficiencies. We report the case of a 60-year-old female with a history of rheumatic heart disease who underwent mitral valve replacement (MVR) and was on Acitrom (acenocoumarol) as long-term anticoagulation prophylaxis. She presented with chronic, recurrent painful skin lesions involving the right lower limb, buttocks, and bilateral axillae. These lesions evolved from hyperpigmentation to ulcerative necrosis over a span of two years. Laboratory investigations revealed deranged coagulation parameters, and histopathological examination confirmed the diagnosis of WISN. Upon clinical suspicion, Acitrom was promptly discontinued, and the patient was switched to low molecular weight heparin. Aggressive wound care, including daily dressings and debridement, was initiated. The patient’s condition gradually improved, and the necrotic lesions began to heal. This case highlights the importance of early recognition and prompt intervention in managing WISN. Timely discontinuation of warfarin and initiation of heparin therapy, along with supportive wound care, are crucial for favourable outcomes. This condition underscores the need for close monitoring of anticoagulation therapy and early diagnosis to prevent irreversible damage.