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

Technical Summary: Suspected Warfarin-Induced Leukocytoclastic Vasculitis in a Patient with Double Mechanical Valve Replacement

Problem Statement
Warfarin remains the essential, often sole, long-term anticoagulant for patients with mechanical prosthetic heart valves, particularly in resource-limited settings where newer alternatives are inaccessible. While generally safe, warfarin can rarely induce leukocytoclastic vasculitis (LCV), a small-vessel immune complex-mediated vasculitis. This presents a critical therapeutic dilemma: discontinuing warfarin to manage the hypersensitivity reaction risks catastrophic prosthetic valve thrombosis and systemic embolization, especially in patients with double mechanical valve replacements who require uninterrupted anticoagulation. Furthermore, in low-resource environments, the lack of histopathological confirmation (skin biopsy) complicates the diagnosis, forcing clinicians to rely on clinical judgment.

Methodology
This paper presents a single case report of a 30-year-old male with chronic rheumatic heart disease who underwent successful double mechanical valve replacement (mitral and aortic). The patient was maintained on warfarin with stable INR control (2.5–3.5) for three months.

• Clinical Presentation: The patient developed a sudden purpuric, pruritic skin rash suggestive of LCV.
• Diagnostic Approach: Due to the unavailability of skin biopsy in the local setting, the diagnosis was established through exclusion. Comprehensive evaluation ruled out autoimmune diseases, infectious causes (bacterial/viral), and metabolic disorders. Laboratory findings included a markedly elevated INR (>6), mild prolongation of PT/aPTT, and a reactive thrombocytosis, while renal and hepatic functions remained normal.
• Intervention Strategy: Warfarin was temporarily withheld for two days. Upon stabilization, it was reintroduced at a reduced dose. The initial alternating dose regimen (3 mg/3.5 mg) was adjusted to a consistent 3 mg daily dose.
• Monitoring: The patient underwent close clinical and laboratory follow-up over a two-week period to monitor skin lesion resolution and INR levels, while ensuring no thromboembolic events occurred.

Key Results

• Clinical Improvement: Following the temporary interruption and dose reduction of warfarin, the patient's cutaneous lesions showed marked improvement. Within one week, pruritus and rash severity decreased; by two weeks, there was approximately 70% resolution of skin lesions with no new formations.
• Safety Outcome: Throughout the observation period, the patient remained clinically stable. Crucially, there were no thromboembolic events, prosthetic valve dysfunctions, or signs of valve thrombosis despite the brief interruption and dose modification of anticoagulation.
• Diagnostic Confirmation: While histopathological confirmation was impossible due to resource constraints, the temporal association between warfarin exposure and symptom onset, combined with the exclusion of other etiologies and the positive response to dose adjustment, strongly supported the diagnosis of suspected warfarin-induced LCV.

Significance and Claims
The authors position this case as a rare but clinically significant illustration of the challenges in managing adverse drug reactions in high-risk anticoagulation scenarios within resource-limited settings.

• Diagnostic Pragmatism: The paper claims that in the absence of biopsy capabilities, a diagnosis of warfarin-induced LCV can be reasonably supported by temporal association, exclusion of alternative causes, and clinical response to management changes.
• Therapeutic Strategy: Contrary to the standard approach of permanent discontinuation for drug-induced LCV, the authors suggest that for patients with mechanical heart valves where anticoagulation cannot be stopped, a strategy of "temporary interruption followed by cautious reintroduction at a lower dose" may be a viable, pragmatic approach to balance hypersensitivity risks against thrombotic dangers.
• Literature Gap: The report highlights a gap in current guidelines, noting that while bleeding and thrombotic complications are well-addressed, rare immune-mediated reactions like warfarin-induced LCV in mechanical valve patients receive limited attention.
• Contextual Relevance: The case underscores the reality of managing complex cardiac conditions in endemic rheumatic and low-resource regions, demonstrating that careful clinical reasoning and individualized risk-benefit assessment can yield favorable outcomes even without advanced diagnostic tools.

The authors conclude with modesty, acknowledging that while their findings offer practical clinical insight, larger studies and additional case reports are necessary to define optimal management strategies for this rare complication. They do not claim to have established a new standard of care, but rather to have provided a documented example of successful management under constrained circumstances.