Comparison of mycology between different types of chronic rhinosinusitis

Background:The aim of this study was to culture fungi from the nasal discharge of patients with chronic rhinosinusitis (CRS) using both a traditional and Ponikau et al's method, and subsequently compare the culture results between CRS with nasal polyps (CRSwNPs) and without nasal polyps (CRSsNPs), and between eosinophilic and noneosinophilic CRS. Methods:Eighty-one CRS patients with CRS who underwent functional endoscopic sinus surgery were enrolled. Before surgery, the severity of each patient's CRS was evaluated through an endoscopic examination and CT scan. Swab samples were collected from the middle meatus for traditional fungal cultures using cotton-tipped sticks. Afterward, the ipsilateral nasal cavity was irrigated, with the irrigated fluid processed using Ponikau et al's method for fungal culture. Results:The endoscopic and CT scores were significantly higher in CRSwNPs than CRSsNPs, but were not different between eosinophilic CRS and noneosinophilic CRS. Using Ponikau et al's method, 61/81 (75.3%) of the specimens grew fungi. Among them, 20 of 32 (62.5%) CRSwNPs specimens and 41 of 49 (83.7%) CRSsNPs specimens grew fungi. For eosinophilic CRS specimens, 35 of 46 (76.1%) grew fungi, and 26 of 35 (74.3%) noneosinophilic CRS specimens grew fungi. The fungal culture rate was borderline significantly higher in CRSsNPs than CRSwNPs (p = 0.058) but was not significantly different between eosinophilic CRS and noneosinophilic CRS (p = 1). However, Cladosporium was significantly more common in CRSsNPs than CRSwNPs (p = 0.048). Conclusion:Our results showed that the mycology of CRS was different between CRSwNPs and CRSsNPs.