Effect of ESS on Olfactory Threshold of Patients with CRS without Nasal Polyps

Objectives: Chronic rhinosinusitis (CRS) is characterized by a long-time inflammatory disease of nasal and sinus mucosa. Olfactory dysfunction is common among CRS patients with a prevalence ranging from 48% to 83%. We aimed to assess the effect of ESS on olfactory function of patients with chronic rhinosinusitis without nasal polyps. Method: This randomized clinical trial was conducted on 30 patients with chronic rhinosinusitis without nasal polyps. Patients were randomly allocated to two intervention and control groups; patients in intervention group underwent endoscopic sinus surgery by a single surgeon and control group continued standard treatment with nasal irrigation of normal saline (4 times daily) and nasal corticosteroids (one puff in each nostril daily). Olfactory threshold was evaluated using smell threshold test (STT) before, one month and three months after intervention. Results: Eventually 33 patients with a mean age of 42.70 ± 15.50 years in intervention and 43.12 ± 11.50 years in control group underwent analysis (p value=0.930). Mean olfactory threshold was 2.79 ± 0.73 in intervention and 2.67 ± 1.05 in control group prior to intervention (p value=0.345). Mean change of olfactory threshold was 0.30 ± 0.79 in intervention and 0.38±1.09 in control group one month after intervention (p value=0.214). Mean change of olfactory threshold was 0.13 ± 0.94 in ESS and 0.33 ± 0.60 in control group three months after intervention (p value=0.196). Conclusion: Our study revealed that changes in olfactory threshold were not significantly different between two ESS and standard medical therapy groups one and three months after intervention.