Prevalence of confirmed asthma varies in chronic rhinosinusitis subtypes.

BACKGROUND: Chronic rhinosinusitis (CRS) and asthma describe inflammation of the upper and lower airway, respectively. Not surprisingly, the prevalence of CRS and asthma has been linked, with up to 50% asthma prevalence in CRS with nasal polyposis (CRSwNP) patients. However, these prevalence rates do not address subtypes of CRSwNP including allergic fungal rhinosinusitis (AFRS). This study sets out to objectively determine asthma prevalence in CRS subtypes prospectively.

METHODS: A prospective prevalence study of adult CRS patients was conducted over a 1-year period at a tertiary care center. Patients were grouped into CRSwNP, CRS without nasal polyposis (CRSsNP), or AFRS. Patients were administered the Asthma Screening Questionnaire (ASQ) and asthma was confirmed by pulmonary function testing (PFT) if positive on the ASQ. Chi square analysis was performed to compare the asthma prevalence among the CRS subtypes.

RESULTS: A total of 410 patients (age 48.1 ± 16.4; 53.5% male) were included. Of these, 178 (43.4%) had CRSwNP, 166 (40.5%) had CRSsNP, and 66 (16.1%) met criteria for AFRS. Analysis revealed that 48.3% of CRSwNP patients, 16.5% of CRSsNP patients, and 23.6% of AFRS patients had asthma confirmed by PFTs. Chi square analysis showed a significant difference in asthma prevalence between CRSwNP and AFRS (p = 0.0016) and CRSwNP and CRSsNP (p = 0.0000), but no significant difference between CRSsNP and AFRS (p = 0.2380).

CONCLUSION: There is a significant difference in the prevalence of asthma between CRSwNP and AFRS, suggesting a fundamental distinction in their etiologies despite similar immunologic profiles. Further efforts to delineate these biological disparities are underway.