Clinical characteristics and surrogate markers of eosinophilic chronic rhinosinusitis in Southern China

The surrogate markers for subclassifying eosinophilic chronic rhinosinusitis (ECRS) and non-ECRS remain elusive. We herein performed a cross-sectional study to assess the clinical implication of clinical symptoms, CT findings, blood eosinophil (EOS) examination based on histological examination of tissue eosinophilia in 105 adult CRS patients (including 72 with nasal polyps and 33 without nasal polyps) in southern China. We found the mean score of smell loss was significantly higher in ECRS subgroup than those in non-ECRS subgroup (p < 0.05), whereas the average ethmoid osteitis index in non-ECRS subgroup was significantly higher than that in ECRS subgroup (p < 0.05). Moreover, we found both the mean blood EOS number and ratio were significantly higher in ECRS subgroup than those in non-ECRS subgroup (p < 0.05). By applying receiver operating characteristic (ROC) curve analysis, we found blood EOS number had a sensitivity of 84.9 % and specificity of 84.4 % area under the curve (AUC): 0.873] at the cutoff level of 0.16 × 10⁹/L, and blood EOS ratio had a sensitivity of 89.0 % and specificity of 84.4 % (AUC: 0.863) at the cutoff level of 2.05 % in this cohort. Our findings indicated that smell loss score, ethmoid osteitis index and blood EOS number and ratio may be used for the differential diagnosis of ECRS as the surrogate markers.