Olfactory dysfunction by COVID-19

Abstract

Olfactory dysfunction is known as the important initial symptom of COVID-19. It is more frequent in mild to moderate cases than in severe cases leading to artificial respiration, and in some patients it is the only COVID-19 symptom. More than half of the patients regain olfactory function within 2 weeks, but some patients remain symptomatic for a long time. The clinical features of the COVID-19 olfactory dysfunction are similar to those of post viral olfactory disorder, but the former is distinct from the latter in that olfactory dysfunction occur in a young population. Anti-inflammatory treatments such as steroids are recommended in the early stages of the disease, and in the case of persistent symptoms, olfactory stimulation therapy is recommended in addition to oral medication such as Chinese herbal medicine, zinc preparations, and vitamins.