Antineutrophil Cytoplasmic Antibody-Negative Eosinophilic Granulomatosis With Polyangiitis in a Pediatric Patient.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare pediatric vasculitis that can be difficult to diagnose, especially when antineutrophil cytoplasmic antibody (ANCA) is negative. We describe the case of a 10-year-old girl with severe asthma, recurrent leukocytoclastic vasculitis, peripheral eosinophilia, and pulmonary nodules. Infectious and immunologic workup was unremarkable, and skin biopsy confirmed eosinophilic vasculitis. She was diagnosed with ANCA-negative EGPA based on the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria and started on high-dose corticosteroids with plans for mepolizumab maintenance. This case highlights the diagnostic challenges in pediatric EGPA, the masking effects of biologic therapy, and the importance of multidisciplinary evaluation for early recognition and optimal management.