The Role of Home Fungal Exposure in Allergic Fungal Rhinosinusitis

Background: Allergic fungal rhinosinusitis (AFRS) is disproportionately identified in patients of low socioeconomic status living in warm, humid climates, and is thought to occur in response to environmental fungal species. Objective: We hypothesized that micro-geographic differences in fungal exposure contribute to the pathogenesis of AFRS, and compared home fungal exposure of patients with AFRS to normative data and controls. Methods: Comprehensive prospective enrollment and data capture was completed in 70 patients. Patients with AFRS were compared to a control population with chronic rhinosinusitis with nasal polyposis (CRSwNP) and comorbid atopy. Comprehensive demographics, 22-item sino-nasal outcomes test (SNOT-22) questionnaires, and endoscopy scores were compiled. Using a test strip collection system, a home fungal assessment was completed for each patient, along with detailed questions related to home condition. Results: Patients with AFRS were more likely to be younger (p<.001), African American (p<.001), from a lower income bracket (p <.012), and less likely to own their home (p <.001). There were no differences in prior surgeries (p=.432), endoscopy scores (p =.409) or SNOT-22 scores (p =.110) between the groups. There were no differences in overall fungal counts between patients with AFRS and controls (p =.981). AFRS patients had a higher prevalence of Basidiospores than controls (p =.034). Conclusion: This study failed to detect differences in total home fungal exposure levels between those with AFRS and atopic CRSwNP, despite differences in socioeconomic status. This suggests that absolute fungal levels may not be the primary driver in development of AFRS, or that the fungal detection strategies utilized were not representative of patients’ overall fungal exposure.