Oral Corticosteroids and Adverse Events in Chronic Rhinosinusitis With Nasal Polyps

Importance: Oral corticosteroids are commonly used in the management of chronic rhinosinusitis with nasal polyps to control inflammation. However, evidence on the long-term safety of repeated or high-dose oral corticosteroid exposure in this population remains limited. Objective: To investigate the association between oral corticosteroid exposure and systemic adverse events in patients with chronic rhinosinusitis with nasal polyps. Design, Setting, and Participants: A retrospective, nationwide, nested case-control study included adult patients (≥20 years) with incident chronic rhinosinusitis with nasal polyps, excluding those with prior immune-mediated diseases or outcome diagnoses, using the Korean Health Insurance Review and Assessment Service database (2010-2023). Data analysis was conducted from March 2025 to April 2026. Patients who developed adverse events (case patients) were matched 1:10 with controls by age, sex, and diagnosis date. Exposures: Oral corticosteroid exposure was quantified using 3 metrics: exposure intensity (annual duration: low [≤30 days], moderate [31-90 days], or high [>90 days]), cumulative dose (90 days per year) was associated with a significantly increased risk of avascular bone necrosis, osteoporosis, and pneumonia. A cumulative dose greater than 1.0 g per year was associated with a 23% higher overall adverse event risk (adjusted odds ratio, 1.23; 95% CI, 1.11-1.36) and increased risks of avascular bone necrosis, pneumonia, dyslipidemia, heart failure, hypertension, and type 2 diabetes. Prescription frequency was not independently associated with adverse event risk. Conclusions and Relevance: In this nested case-control study within a nationwide cohort of patients with chronic rhinosinusitis with nasal polyps, higher oral corticosteroid exposure, in terms of annual duration and cumulative dose, was associated with an increased risk of systemic adverse events, particularly musculoskeletal and infection-related complications. These findings underscore the need for steroid-sparing treatment strategies for long-term management of chronic rhinosinusitis with nasal polyps.