Rhinosinusitis in Adults With Autoimmune Diseases: A Scoping Review

INTRODUCTION: Chronic rhinosinusitis (CRS) and autoimmune diseases share inflammatory pathways, yet the scope of their association across diverse autoimmune conditions remains incompletely characterized. This scoping review aimed to map the breadth of evidence examining relationships between autoimmune diseases and rhinosinusitis, including epidemiologic associations, mechanistic pathways, and clinical outcomes. METHODS: Following PRISMA-ScR guidelines, we systematically searched electronic databases for studies examining associations between autoimmune disorders and CRS. Data were extracted on study design, autoimmune conditions, outcomes, and key findings. RESULTS: Twenty-four studies were included, comprising different types of studies. Rheumatoid arthritis demonstrated the most consistent association with CRS (OR: 1.39-1.9). Sjögren's syndrome showed elevated CRS risk (HR: 1.70-2.51), while systemic lupus erythematosus (SLE) and ankylosing spondylitis demonstrated moderate associations. IgG4-related disease emerged as a distinct CRS phenotype with 32%-59% sinonasal involvement responding to immunosuppression. Mendelian randomization studies identified causal relationships between multiple sclerosis, type 1 diabetes, celiac disease, hypothyroidism, and CRS, mediated by IL-10, CXCL10, and CD6. CRS without nasal polyps showed stronger autoimmune associations than CRS with nasal polyps. Autoimmune disease was associated with worse quality of life and more frequent acute exacerbations. CONCLUSION: Substantial evidence supports associations between multiple autoimmune disorders and rhinosinusitis through shared Th1/Th17 pathways and mucosal immune dysregulation. Future research should focus on prospective phenotyping, biomarker integration, and targeted screening strategies.