A rare case of pediatric ANCA-associated vasculitis presenting as rapid-onset bilateral orbital inflammation leading to compartment syndrome and profound bilateral visual loss.

Pediatric-onset anti-neutrophil cytoplasmic antibody (ANCA) vasculitis is a very rare condition, particularly cases presenting with ophthalmic involvement. We report a case of severe orbitopathy secondary to anti-proteinase 3 (PR3) ANCA-associated vasculitis in an 8-year-old boy with severe autism. Despite emergency interventions and immunosuppressive treatment, the patient suffered profound bilateral vision loss.