Pathogenesis and Biomarkers of Eosinophilic Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is divided into CRS with nasal polyp formation (CRSwNP) and CRS without NP formation (CRSsNP) according to the phenotype classification. CRS is also divided into type 1/type 2/type 3 according to the endotype classification. CRSwNP and type 2 CRS are caused by eosinophilic inflammation in most cases, and are intractable. Useful biomarkers for such cases of eosinophilic CRS (eCRS) are desired for predicting their severity and postoperative courses.