Longitudinal study of olfactory dysfunction among COVID-19 patients in a single tertiary centre in Malaysia

Aim: The aim of the study was to outline the longitudinal outcomes of olfactory dysfunction amongst patients with coronavirus disease 2019 (COVID-19) in a single tertiary centre in Malaysia. Materials and methods: Adults patients who tested positive for COVID-19 via reverse transcription-polymerase chain reaction and were admitted to Hospital Sungai Buloh, Malaysia, were recruited in this study. The patients completed a questionnaire via telephone interview comprising the following details: age, sex, ethnicity, comorbidities, general and otorhinolaryngological symptoms, and onset and duration of olfactory and gustatory dysfunction. The patients with persistent olfactory and gustatory dysfunction at the time of the initial interview were followed up every 3 to 5 days until resolution. Results: A total 185 patients were included in this study out of 378 patients contacted. Ninety patients reported olfactory dysfunction symptoms, with 59 of them complaining of anosmia. The mean age of the participants was 39.52 years (age range: 18–66 years). More than half of the patients with olfactory dysfunction had no comorbidities (55.56%). Of the 90 patients with olfactory dysfunction, 66 patients (73.3%), including 40 males and 26 females, regained their olfactory function completely within 2 weeks. The remaining 24 patients were contacted after 4, 8, and 12 weeks. Ten patients (11.1%) were found to have recovered their sense of smell after one month, while 5 patients (5.56%) recovered within 2 months, and 1 patient (1.11%) recovered in 3 months. Conclusion: Complete recovery was noted in 73% of the patients within a period of 2 weeks, whereas persistence of symptoms was noted in 6 patients (6.67%) after 3 months.