Reports of COVID-19-related olfactory dysfunction describe a sudden onset of olfactory impairment, which may be in the presence or absence of other symptoms. The possibility that olfactory dysfunction could act as a marker for disease. When COVID-19-related olfactory dysfunction improves spontaneously, specific treatment may not be required. However,when impairment persists beyond 2 weeks, it may be reasonable for treatment to be considered. The efficacy of available treatments for patients with COVID-19-related olfactory dysfunction is unknown. Olfactory training involves repeat and deliberate sniffing of a set of odorants (commonly lemon, rose, cloves, and eucalyptus) for 20 seconds each at least twice a day for at least 3 months (or longer if possible). Studies have demonstrated improved olfaction in patients after olfactory training. Olfactory training can be considered for patients with persistent COVID-19-related olfactory dysfunction. Some evidences shown that corticosteroid treatment would benefit post-COVID-19 olfactory dysfunction but the evidences is not adequate. Until now, the efficacy of oral corticosteroids is controversial. This study investigate the efficacy and the safety of oral corticosteroids and olfactory training as a treatment for patients with COVID-19-related olfactory dysfunction.
Studies have demonstrated that patients with COVID-19- related olfactory dysfunction could improve the olfactory function after olfactory training. But the efficacy of oral corticosteroids is controversial. Some evidences shown that corticosteroid treatment would benefit post-COVID-19 olfactory dysfunction and the purpose of this study is to evaluate its efficacy.