Emergence and Evolution of Olfactory and Gustatory Symptoms in Patients with COVID-19 in the Outpatient Setting

The present study aimed at evaluating the prevalence of general and sinonasal symptoms in patients with olfactory symptoms and mild coronavirus disease-2019 (COVID-19) and determining the patterns in emergence and resolution of olfactory/gustatory symptoms relative to general and sinonassal symptoms. This was a prospective cross-sectional study conducted at the outpatient otorhinolaryngology clinic at a COVID-19-designated referral Hospital. We included consecutive patients with new-onset olfactory dysfunction and positive polymerase chain reaction (PCR) assay of COVID-19. We asked the patients to fill in a questionnaire about general and sinonasal symptoms in association with anosmia, hyposmia or hypogeusia, and recorded the time course of the olfactory/gustatory symptoms during 2-weeks of follow-up. 76 patients with average age of 38.5 ± 10.6 years were included. Majority of participants (94.7%) had general or sinonasal symptom. There was anosmia in 60.5% and hyposmia in 39.5%, with sudden onset of olfactory symptoms reported in 63.2% of patients. During the follow-up, 30.3% of patients completely and 44.7% partially recovered from anosmia/hyposmia. Regardless of whether the general or olfactory symptoms appeared initially, the general symptoms resolved first while a degree of olfactory dysfunction persisted during the follow-up. Our study showed that hyposmia and anosmia in mild COVID-19 are frequently associated with general and sinonasal symptoms and tend to persist longer than the general and sinonasal symptoms during the course of the disease.