Cumulative incidence of chronic rhinosinusitis and association with allergic multimorbidity in a tertiary center cohort of patients with allergic rhinitis: a long-term analysis

Background Allergic rhinitis (AR) affects up to 50% of adults globally. This study was undertaken to evaluate cumulative incidence of chronic rhinosinusitis (CRS) in patients with AR and to investigate the association between CRS and clinical features of AR, sensitization patterns, concomitant atopic comorbidities and AR severity. Method This retrospective, observational, multicenter study included consecutive adult patients with a diagnosis of AR without CRS at first assessment. Data covering clinical information from AR onset to the last follow-up were collected. Results Out of the 198 patients included (54.0% female, median age at AR diagnosis 19 years old, IQR 11–30), CRS developed in 65.2% of patients during follow-up. Among those who developed CRS, 51.2% had radiological confirmation, and 31.0% were diagnosed with CRS with nasal polyposis (CRSwNP). Multivariate analysis revealed no independent predictors of CRS at the time of AR diagnosis (Hazard ratio (HR) with [95% confidence intervals (CI)] 1.24 [0.68–2.25], age at AR diagnosis (per year change) 1.00 [0.98–1.02], atopic morbidities 1.81 [0.8–4.11], and polysensitization 0.76 [0.8–1.58]). At last follow up (median 19 [IQR 9-29] years from AR diagnosis), AR was moderate-persistent in 47.4%. Patients with CRSwNP have a higher proportion of asthma (77.5% vs 43.8%, p=0.0005) and ASA hypersensitivity (27.5% vs. 5,6%, p=0.0010) as compared to CRSsNP. Overall, only CRS was independently associated to moderate-persistent AR at last follow-up (HR 2.90 [1.51, 5.56]). Conclusion Almost two-thirds of subjects with AR develop CRS during the disease course. Years after AR diagnosis, CRS is the only independent factor associated with moderate-persistent AR, increasing almost three times its risk.