Suspected Warfarin-Induced Leukocytoclastic Vasculitis in a Patient with Double Mechanical Valve Replacement: A Rare Anticoagulation Dilemma in a Resource-Limited Rheumatic Setting

<title>Abstract</title> <p>Background: Warfarin remains the cornerstone of long-term anticoagulation in patients with mechanical prosthetic valves, particularly in resource-limited settings where therapeutic alternatives may be unavailable or unaffordable. Although generally well tolerated, warfarin can rarely induce leukocytoclastic vasculitis (LCV), posing a significant therapeutic challenge when interruption of anticoagulation may increase the risk of prosthetic valve thrombosis. We report a suspected case of warfarin-induced leukocytoclastic vasculitis in a patient with double mechanical valve replacement, highlighting the complexity of balancing adverse drug reactions against thromboembolic risk. Case Presentation: A 30-year-old man with chronic rheumatic heart disease underwent successful double mechanical valve replacement (mitral and aortic valves) and was maintained on warfarin therapy with stable INR control for three months. He later developed a sudden purpuric pruritic skin rash clinically suggestive of leukocytoclastic vasculitis. Evaluation excluded autoimmune and infectious causes, while laboratory tests revealed markedly elevated INR (&gt; 6) with otherwise preserved renal and hepatic function. Due to limited resources, skin biopsy was not available. Warfarin-induced leukocytoclastic vasculitis was suspected based on the temporal association and exclusion of other etiologies. Warfarin was temporarily withheld and restarted at a lower dose, leading to marked improvement of the skin lesions within two weeks without thromboembolic complications or prosthetic valve dysfunction during follow-up. Conclusion: Suspected warfarin-induced leukocytoclastic vasculitis is a rare but important diagnostic and therapeutic consideration in patients requiring lifelong anticoagulation for mechanical heart valves. In resource-limited settings, clinical judgment may guide diagnosis when histopathologic confirmation is unavailable. Careful temporary interruption and cautious reintroduction of warfarin may represent a pragmatic strategy to balance bleeding, hypersensitivity, and thrombotic risks. Clinical Trial Registration Not applicable.</p>