Objectives: The aim of this study was to assess the effect of topical steroids on acute-onset olfactory dysfunction in patients infected with COVID-19.
Design and setting: Systematic review and meta-analysis of cohort studies.
Participants: Patients infected with COVID-19.
Main outcome measures: PubMed, Embase, the Web of Science, SCOPUS, Cochrane database and Google Scholar were searched for articles up to September 2021. We analysed studies comparing the improvement of olfactory dysfunction between topical steroid treatment and control groups (placebo or no treatment). In addition, we performed a subgroup analysis by study type.
Results: The improvement of olfactory score at 2 (standardised mean difference [SMD] = 0.7272, 95% confidence interval = [0.3851, 1.0692], p < .0001, I2 = 62.1%) and 4 weeks post-treatment (SMD = 1.0440 [0.6777, 1.4102], p < .0001, I2 = 61.2%) was statistically greater in the treatment than control group. However, there was no significant difference (odds ratio [OR] = 1.4345 [0.9525, 2.1604], p = .0842, I2 = 45.4%) in the incidence of fully recovery from anosmia/hyposmia between the treatment and control groups. In subgroup analysis, there were no significant differences in the improvement of olfactory score at 4 weeks post-treatment (OR = 0.6177 [0.1309, 1.1045] vs. 0.1720 [0.8002, 1.5438], p = .0761) or the incidence of full recovery from anosmia/hyposmia (OR = 1.8478 [0.6092, 5.6053] vs. 1.3784 [0.8872, 2.1414], p = .8038) between randomised and non-randomised controlled trials.
Conclusions: Although this meta-analysis found that topical steroids improved the acute-onset olfactory dysfunction caused by COVID-19, there was no difference in the rate of full olfactory recovery between treated and control patients.
Keywords: coronavirus infections; nasopharynx; saliva; specimen handling; treatment outcome.
© 2022 John Wiley & Sons Ltd.