Introduction:
Among other etiologies, such as the airway obstruction and neural
disorders, viral illnesses have always been the most common cause of
prolonged olfactory dysfunction (POD). The emerging coronavirus disease
2019 (COVID-19), which is now increasingly recognized to be accompanied
by an impairment in odor sensation, may have contributed to an increase
in the overall prevalence of POD, but to what extent is unknown. While
once thought to have a good prognosis, recent reports on long-term
follow-up data estimate that a significant proportion of patients with
the COVID-19-related odor sensation impairment, ranging from 1% to
48%1,2, develop POD. In this study, we evaluated the
relative burden of the COVID-19-related disease in a single-centered
cohort consisting of patients with POD of previously undetermined
etiology. The clinical characteristics of COVID-19-related POD were
compared with those of POD from other etiologies.