Prevalence and Outcome of Olfactory Dysfunction in COVID-19 Patients in a Multiracial Asian Setting

Objective: This study aimed to outline the prevalence and the outcome of olfactory dysfunction in a multiracial Asian setting. Methods: The olfactory function of adult patients (above 18 years of age) who tested positive for coronavirus disease 2019 via reverse transcription-polymerase chain reaction and were admitted to a tertiary center was assessed through a telephone-based interview. Patients with olfactory dysfunction at the time of the initial interview were followed up after 2, 4, 8, and 12 weeks. Results: A total of 356 patients completed the study, of which 94 coronavirus disease 2019-positive patients with new-onset olfactory dysfunction were included in this study. The prevalence of olfactory dysfunction in this study is 26.4%. Female predominance and younger age group were demonstrated. Malay patients were found to be the predominant race affected by coronavirus disease 2019 by 83%. The improvement of olfactory dysfunction was significant after 2 weeks as 84% improved. After 3 months of follow-up, 6.4% had persistent symptoms, of which 33.33% had parosmia and 66.67% had anosmia. None of the patients had olfactory dysfunction prior to coronavirus disease 2019or had a history of recurrent nasal symptoms. None of the patients received the coronavirus disease 2019 vaccination. Conclusion: The prevalence of olfactory dysfunction among coronavirus disease 2019patients is 26.4%, whereby the Malay population were the predominant ethnic group involved. 84% of patients recovered after 2 weeks. After 3 months of follow-up, 6.4% of patients still have persistent olfactory dysfunction.