Effective Management of a Rare Case of Pediatric ANCA-Associated Vasculitis With Rituximab and Mycophenolate Mofetil

BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare pediatric condition that can present with rapidly progressive glomerulonephritis and is characterized by necrotizing crescentic glomerulonephritis. While there are no specific pediatric treatment guidelines, rituximab has shown promising benefits in the management of pediatric AAV. This report presents a case of AAV in a 6-year-old girl treated with rituximab and mycophenolate mofetil, resulting in remission that was maintained at 5-year follow-up. CASE REPORT A 6-year-old girl with eczema herpeticum presented with progressive bilateral lower extremity pain, weakness, and intermittent fever and later developed microscopic hematuria. Initial workup revealed proteinuria, elevated inflammatory markers, and renal biopsy findings of pauci-immune crescentic glomerulonephritis, with positive perinuclear ANCA and myeloperoxidase antibodies, confirming AAV. She was initially treated with corticosteroids without improvement, but subsequent rituximab induction followed by mycophenolate mofetil maintenance resulted in clinical improvement. At 5-year follow-up, she remained in remission while receiving enalapril and annual rituximab therapy. CONCLUSIONS This report presents a rare occurrence of AAV in a pediatric patient and demonstrates the challenges in treating this condition given the lack of pediatric-specific treatment protocols. Further research and case reports are essential in the development of standardized and evidence-based treatment strategies tailored to the pediatric population. This case highlights that AAV, while rare in children, can be effectively managed with rituximab and mycophenolate mofetil to achieve long-term remission.