Effect of oral zinc and steroids on long COVID hyposmia and hypogeusia.

Objective: We studied the prognosis of olfactory and gustatory dysfunctions in patients with long COVID (Coronavirus Disease 2019) after treatment with oral zinc and steroids.

Methods: We measured olfactory and gustatory functions of long COVID patients at their first visits, and after 2-4 months of treatment with oral zinc and steroids using the traditional Chinese version of the University of Pennsylvania Smell Identification Test and the Waterless Empirical Taste Test. We also assessed by phone the recovery of olfactory and gustatory functions at a mean of about 10 months of follow-up.

Results: Among our 71 long COVID patients, 34 complained of loss of smell and taste. Their objective test results showed 88.2% hyposmic, 23.5% hypogeusic at the first visit. After treatment, 77.8% of the patients were hyposmic, and 16.7% were hypogeusic. After a mean follow-up of 10.35 months, 91.2% of the patients reported improvement in their olfactory function. Among the 36 patients who had complained only of smell loss, the objective test results showed 75% hyposmic at their first visit. After treatment, 71.4% of the patients were hyposmic. After a mean of 10.42 months of follow-up, 77.8% of the patients reported improvement in their olfactory function. Only one patient complained of taste loss.

Conclusions: We found that olfactory dysfunction in most long COVID patients persisted for more than 10 months.