Corticosteroid nasal irrigation as early treatment of olfactory dysfunction in COVID-19: A prospective randomised controlled trial.

Abstract

This study aimed to evaluate the efficacy of corticosteroid irrigation compared to saline to no nasal irrigation in COVID-19 patients with olfactory loss. A randomised controlled study was conducted at the Otolaryngology-Head & Neck Surgery Department, Ramathibodi Hospital, Faculty of Medicine, Mahidol University. Two hundred thirty-seven COVID-19 participants with a new-onset smell loss were recruited into the study. Two hundred twenty-two participants met the inclusion criteria and were randomised into three groups: corticosteroid irrigation, saline irrigation and no treatment. The primary outcome was the mean difference in the smell sensation score among the groups after treatment at 1, 2 and 6 weeks. The secondary outcomes measurements included (1) a self-rating quality of life (QOL)-related smell dysfunction score, (2) the change over time in smell sensation score and self-rating QOL-related smell dysfunction score and (3) the median time to complete recovery of smell loss. The mean differences in smell sensation scores among the three groups were not statistically significant at any follow-up period. The mean score of self-rating QOL-related smell dysfunction in the corticosteroid group was significantly better than the other groups at 1 week. The change of outcome scores showed significant improvement over time, regardless of the treatments. The median time to complete smell recovery was similar: 3 weeks. This study emphasised that corticosteroid nasal irrigation is not superior to saline or no nasal irrigation in restoring the sense of smell in COVID-19-associated olfactory loss.