Immunoglobulin G4 related disease isolated to the nasal cavity: a rare cause of nasal obstruction

Background: Immunoglobulin G4 related disease is a rare condition. Cases involving the sinonasal region are exceptionally uncommon. This paper describes a case of immunoglobulin G4 related disease isolated solely to the nasal cavity. Methods: Case report and literature review. Results: A 34-year-old man presented with painless, progressive bilateral nasal obstruction. Clinical examination and imaging findings demonstrated bilateral submucosal swelling of the anterior septum and right external nasal wall. Biopsy revealed immunoglobulin G4 related disease. The patient responded to oral corticosteroids initially, followed by long-term methotrexate. Conclusion: To the best of our knowledge, this case represents the first report in the literature of immunoglobulin G4 related disease isolated solely to the nasal cavity.