Fatal Arteriovenous Fistula Rupture in Renal-Predominant Eosinophilic Granulomatosis With Polyangiitis: A Case of Delayed Diagnosis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis characterized by asthma, eosinophilia, and multisystem involvement. Renal manifestations are relatively uncommon but may be severe and rapidly progressive, and fatal hemorrhage from arteriovenous fistulas (AVFs) represents an uncommon yet catastrophic complication in patients with advanced kidney disease. We report a case of a 70-year-old man with long-standing asthma, chronic rhinosinusitis with nasal polyposis, marked eosinophilia, and progressive renal failure. After years of fragmented clinical manifestations, a clinical diagnosis of EGPA was considered based on clinical, laboratory, and immunological findings, supported by fulfillment of the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria in the absence of histopathological confirmation, in the setting of rapidly progressive renal dysfunction. Induction immunosuppressive therapy with high-dose corticosteroids and cyclophosphamide was initiated. Due to advanced chronic kidney disease and the anticipated need for renal replacement therapy, a left radiocephalic AVF was constructed. Seventeen days later, the patient experienced spontaneous fistula rupture at home, resulting in massive hemorrhage, refractory hemorrhagic shock, and death. This case illustrates the consequences of delayed EGPA diagnosis and highlights the possibility of fatal vascular access complications in the setting of active systemic vasculitis, underscoring the importance of careful timing of invasive procedures, heightened clinical vigilance, and structured patient education when planning vascular access in patients with active inflammatory disease.