To investigate the clinical features, treatment strategies, and prognosis of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) with nasal symptoms as the initial manifestation.

A retrospective analysis was conducted on three AAV patients treated at the Department of Otolaryngology-Head and Neck Surgery, Huai’an Hospital Affiliated to Xuzhou Medical University between January 2019 and December 2024. Clinical data, diagnostic and therapeutic interventions, and follow-up outcomes were systematically reviewed.

All patients initially exhibited chronic sinusitis-like symptoms: recurrent epistaxis (n=1) and nasal obstruction with headache (n=2). Pulmonary manifestations (lung nodules, localized calcification, or interstitial changes) were observed in all cases. Case 1 was hospitalized for recurrent epistaxis and diagnosed with chronic sinusitis via sinus CT, and he underwent endoscopic sinus surgery (ESS). Postoperative persistence of epistaxis, headache, and orbital pain prompted ANCA serology testing, which confirmed AAV. Immunosuppressive therapy initiated after rheumatology referral achieved symptom remission, though nasal symptoms recurred during follow-up. Case 2 presented with sinusitis. His nasal obstruction and headache improved after minimally invasive ESS. Persistent cough led to ANCA detection and subsequent immunosuppressive treatment with resolution of symptoms. Case 3 was initially diagnosed with chronic sinusitis and a nasal mass at an external institution. ESS failed to alleviate nasal obstruction/headache. Anti-inflammatory therapy was ineffective. Rheumatology consultation confirmed AAV. Cyclophosphamide and corticosteroid treatment resulted in clinical improvement.

AAV with initial sinonasal involvement typically manifests as nasal obstruction, headache, epistaxis, nasal ulceration, and/or polyposis. Otolaryngologists may reflexively resort to ESS for symptom management, potentially resulting in delayed diagnosis and inappropriate initial management. While ANCA serology testing provides critical diagnostic support, definitive diagnosis requires integrated assessment of clinical manifestations, histopathological findings (where available), and immunological parameters to facilitate early disease confirmation. Multidisciplinary collaboration is essential to mitigate diagnostic errors.