New clinical diagnostic criteria for eosinophilic chronic rhinosinusitis

Chronic rhinosinusitis is a heterogeneous disease. Most cases of chronic rhinosinusitis with nasal polyp(s) (CRSwNP) in Western countries show a strong tendency for recurrence after surgery and pronounced eosinophil infiltration in the nasal polyps. The prevalence of CRSwNP with pronounced eosinophilic inflammation is steadily increasing and is classified as eosinophilic chronic rhinosinusitis (ECRS) in Japan. However, less than 50% of CRSwNP patients in Japan and East Asia show such features. Since the treatment strategy of ECRS differs from that of non-ECRS, clinical diagnostic criteria that distinguish ECRS from non-ECRS are needed.

A total of 124 patients with CRSwNP patients who underwent endonasal sinus surgery were classified as ECRS or non-ECRS according to their clinical characteristics and the clinical features of the two groups were compared. Computed tomography (CT) images of the sinuses were graded according to the Lund-Mackay system. We also graded CT images of the olfactory cleft. Blood examination findings, sinus CT images and asthma complications were analyzed by multivariate logistic regression. Clinical findings that were significantly different between ECRS and non-ECRS were analyzed by receiver operating characteristic curves to determine optimal predictors of ECRS.

Blood eosinophilia, asthma complications and CT image scores were significantly different between ECRS and non-ECRS. In particular, increased blood eosinophil percentage and CT image scores for the posterior ethmoid and the olfactory cleft showed good accuracy as predictors of ECRS. A combination of the cut-off values for three predictors (increased blood eosinophil percentage above the normal range, olfactory cleft score ≥1 and posterior ethmoid score ≥1) indicated high accurate diagnostic ability (sensitivity, 84.6%; specificity, 92.3%).

A set of three clinical findings can differentiate ECRS from non-ECRS with high accuracy, even when these findings are assessed in regular outpatient clinics.