Diagnostic criteria for eosinophilic chronic rhinosinusitis: Comparative analysis and novel scoring system

Background Accurate identification of eosinophilic chronic rhinosinusitis is essentialg because its treatment and prognosis substantially differ from other subtypes. Methods This retrospective observational study included 640 patients who underwent endoscopic sinus surgery for chronic rhinosinusitis in a single tertiary center from January 2021 to December 2022. Receiver operating characteristic curves were generated to compare accuracy, sensitivity, specificity of the novel scoring system, and previous diagnostic criteria (Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis, European Forum for Research and Education in Allergy and Airway Diseases, European Position Paper on Rhinosinusitis and Nasal Polyps, and Sakuma et al.) for predicting eosinophilic chronic rhinosinusitis (ECRS) by tissue eosinophil count ≥70 per high power field. Results Patients were randomly divided into estimation (n = 430) and validation (n = 210) groups. The area under the receiver operating characteristic curve for the novel score was 0.753 (95% confidence interval [CI], 0.670–0.835) in the estimation group, 0.729 (0.629–0.830) in the validation group, and 0.661 (0.584–0.738) in the 20‐fold cross‐validation with the entire dataset. Conclusions We propose a novel scoring system that incorporates three key parameters: “novel score = blood eosinophil (%) + total Lund–Mackay score of anterior ethmoid sinuses + 2 if nasal polyp present” greater than 7 can be reliably used for diagnosing ECRS. This system can facilitate decision‐making processes regarding the administration of oral steroids and biologics targeting type 2 inflammation prior to surgical intervention.