Persisting anosmia after COVID-19 infection: The continuing mystery

Abstract

Background: COVID-19 pandemic has had a massive impact on global health-care systems and economic stability. Smell and taste dysfunction is now recognized as one of the cardinal symptoms of COVID-19. Since the prevalence of olfactory dysfunction in COVID-19 infection varies from place to place, this study was done to find out the prevalence of olfactory dysfunction in COVID-19 infection, and its persistence on follow-up in a tertiary care centre situated in Alappuzha (South India). Methods: The present study was a tertiary hospital based descriptive study. 150 patients with COVID-19 Infection who presented to the centre during a period of 6 months were selected, and their detailed history, clinical findings and investigation results were recorded in a proforma. Follow-up of the patients was done for a period of 2 years. Results: Among the 150 COVID-19 patients 114 (76%) of them had olfactory dysfunction. There were no significant difference in the gender or age distribution, for olfactory dysfunction. Among those with olfactory dysfunction, 88 patients (77.2%) had a faster recovery within 2 weeks. On follow-up, there was persistence of olfactory dysfunction in 2 patients even after 2 years. Conclusion: The prevalence of olfactory dysfunction seen among COVID-19 patients was much more than that described in studies from other places. The persistence of olfactory dysfunction for a long period in some patients is a matter that needs further research to bring out the causative factors. Keywords: COVID-19; Olfactory dysfunction; anosmia; prevalence; persistence