Clinical Characteristics and Hearing Outcomes of Otitis Media With ANCA-Associated Vasculitis: A Four-Group Comparison Including Unclassified Disease

Objective: To characterize clinical features, hearing outcomes, and relapse patterns across disease categories of otitis media with antineutrophil cytoplasmic antibody–associated vasculitis (OMAAV), with particular focus on unclassified OMAAV. Study design: Retrospective cohort study. Setting: Tertiary referral university hospital. Patients: Fifty-six patients (89 ears) diagnosed with OMAAV between 2009 and 2025, classified as eosinophilic granulomatosis with polyangiitis (n=16), granulomatosis with polyangiitis (GPA, n=17), microscopic polyangiitis (n=8), or unclassified OMAAV (n=15). Interventions: Immunosuppressive therapy, including systemic corticosteroids with or without additional immunosuppressants. Main outcome measures: Time from disease onset to treatment initiation, pure-tone audiometric outcomes, and cumulative incidence of otologic and systemic relapse. Results: Patients with unclassified OMAAV demonstrated a significantly longer time to treatment initiation and more severe hearing impairment at presentation compared with those with other subtypes. Across the entire cohort, longer time to treatment initiation was moderately correlated with greater baseline hearing loss. Despite presenting with the most severe hearing impairment, patients with unclassified OMAAV showed hearing improvement comparable to that in the other groups following immunosuppressive therapy. The 3-year cumulative incidence of otologic relapse did not differ significantly among groups. In contrast, systemic relapse occurred most frequently in GPA. Among patients with GPA, temporal analysis revealed heterogeneous patterns of otologic and systemic relapse, and otologic relapse did not consistently precede systemic exacerbation. Conclusions: Unclassified OMAAV is prone to diagnostic delay due to an isolated otologic presentation, resulting in severe hearing loss at onset; however, preserved responsiveness to treatment highlights the importance of early diagnosis and prompt immunosuppressive therapy. Otologic relapse does not consistently precede systemic relapse in granulomatosis with polyangiitis, underscoring the need for careful systemic evaluation regardless of otologic disease activity.