Olfactory disorders in patients with mild to moderate COVID-19: spontaneous recovery in one-month follow up

Objective: In this study, we aimed to evaluate olfactory disorders (OD) and recovery processes in patients with coronavirus disease 2019 (COVID-19) infection at three time periods within one month from the time of diagnosis. Methods: A total of 96 patients with COVID-19 participated in the study. Self-reported changes in olfactory functions and their effects on quality of life (QoL) were evaluated using the National Health and Nutrition Examination Survey, the Questionnaire of Olfactory Disorders-Negative Statements (QOD-NS), and Sino-Nasal Outcome Test (SNOT)-22. At the time of diagnosis, the patients were divided into three groups: anosmia, hyposmia, and no OD (control) group. Subsequently, olfactory functions were retested at the time of the first negative polymerase chain reaction (PCR) control test and one month from the time of diagnosis. Results: During the COVID-19 infection, 68.7% of patients had OD; of these, 37% had anosmia, and 29% had hyposmia. Dysgeusia was found in 44.8% of the patients. OD was the primary symptom in 10.8% of the patients. The QoL scores of those with anosmia and hyposmia were significantly lower than those with no OD in all three surveys (P <.05). The QOD-NS scores of those with OD lasting more than 14 days were significantly lower in all three surveys (P <.05). Of the patients with OD, 4.34% had no spontaneous recovery at the end of the first month. Conclusion: Recovery of OD is faster in patients with hyposmia than in those with anosmia. Although COVID-19related permanent OD is not commonly observed, treatment of OD that lasts for more than 15 days would be beneficial to avoid permanent sequelae.