Akiyama K, et al. - Researchers investigated the efficacy of endoscopic sinus surgery (ESS) for restoring olfaction in eosinophilic chronic rhinosinusitis (ECRS), as defined by new Japanese diagnostic criteria. Further, they sought for the parameters affecting improvement rates. They retrospectively examined 84 patients with ECRS who underwent full-house ESS. They used Toyota & Takagi (T&T) recognition thresholds to determine olfactory function before and 3 months after surgery. The total positive improvement rate in olfaction was 76.2% (64 of 84); there was a significant decrease in the mean T&T recognition threshold from 5.2 ± 1.1 to 3.0 ± 1.8 after surgery. Independent prognostic factors for being in the olfaction refractory group were negative intravenous olfaction test, presence of olfactory cleft lesions, a history of sinus surgery, age ≥ 45 years, and being males.