Olfactory mucosa steroid injection in treatment of post-COVID-19 olfactory dysfunction: a randomized control trial

Abstract

BackgroundOlfactory dysfunction can be a troublesome condition affecting the quality of life of the patient. Post-viral olfactory dysfunction is the most common cause attributing to up to 40% of anosmia. COVID-19 infection commonly causes anosmia in 30–66% of patients. The long-term effect of post-COVID olfactory dysfunction is reported to be increasing in incidence. Steroids are usually used in the treatment of olfactory dysfunction and most commonly used locally in the form of nasal steroid sprays, rinses, or drops. Oral systemic steroids are sometimes used; however, they have several known side effects. Other treatments experimented include giving vitamins, minerals, antioxidants, antivirals, and monoclonal antibodies, in addition to olfactory training, counseling, and acupuncture. In this study, the effect of intranasal steroid injection is studied in post-COVID olfactory dysfunction.ResultsForty patients with olfactory dysfunction post-COVID-19 for more than 3 months were randomly divided into 2 groups. Group A patients received 8 doses of dexamethasone over 2 months (twice weekly) injected near the olfactory mucosa in the nasal septum and middle turbinate, compared to group B who received saline injected in the same way as placebo. Numerically, nasal injection of corticosteroids in group A showed more subjective improvement using the questionnaire of olfactory disorders-negative statement QOD-NS than the control patients in group B but this improvement was statistically insignificant.ConclusionThe use of intranasal corticosteroids injection should be considered in the treatment of post-COVID anosmia.