Livedoid Vasculopathy Mimicking Rheumatoid Vasculitis in a Patient With Active Rheumatoid Arthritis.

Livedoid vasculopathy (LV) is a rare thrombo-occlusive disorder of the dermal microcirculation that may clinically resemble inflammatory vasculitis. In patients with rheumatoid arthritis (RA), the development of painful lower extremity ulcers often raises concern for rheumatoid vasculitis, making histopathological evaluation essential for accurate diagnosis and treatment selection. We present a case of a 45-year-old man with an eight-year history of seropositive RA receiving methotrexate, sulfasalazine, and baricitinib who developed painful lower extremity ulcers, edema, and episcleritis in the setting of high disease activity (Disease Activity Score 28 using C-reactive protein {DAS28-CRP} of 6.23). Given the suspicion of rheumatoid vasculitis, an extensive diagnostic workup was performed. Laboratory studies demonstrated elevated inflammatory markers and negative antineutrophil cytoplasmic antibodies. Skin biopsy revealed vascular wall hyalinization, luminal obliteration, and fibrin thrombi in the absence of inflammatory infiltrates or fibrinoid necrosis, establishing the diagnosis of livedoid vasculopathy. Treatment with systemic glucocorticoids and rituximab, administered according to the standard rheumatoid arthritis regimen, resulted in partial improvement in ocular inflammation, joint symptoms, and cutaneous ulceration. Anticoagulant therapy was not initiated because treatment escalation was primarily directed toward uncontrolled rheumatoid arthritis and severe extra-articular manifestations. Histopathological examination demonstrated vascular wall hyalinization, luminal obliteration, and fibrin thrombi in the absence of significant vascular inflammation or fibrinoid necrosis, establishing the diagnosis of livedoid vasculopathy and excluding rheumatoid vasculitis. Although initial clinical improvement was observed, recurrent ocular symptoms and persistent lower extremity ulceration developed following interruption of biologic therapy. Histopathological confirmation demonstrating thrombotic microvascular occlusion without vascular inflammation was essential for establishing the diagnosis and avoiding misclassification as rheumatoid vasculitis. This case highlights the importance of tissue diagnosis in patients with RA presenting with ulcerative cutaneous lesions and emphasizes the need to consider livedoid vasculopathy in the differential diagnosis of suspected rheumatoid vasculitis.