Anosmia in COVID-19: Mechanisms and Significance

Albert Y Han, Laith Mukdad, Jennifer L Long, Ivan A Lopez, Albert Y Han, Laith Mukdad, Jennifer L Long, Ivan A Lopez

Abstract

The global pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 remains a challenge for prevention due to asymptomatic or paucisymptomatic patients. Anecdotal and preliminary evidence from multiple institutions shows that these patients present with a sudden onset of anosmia without rhinitis. We aim to review the pathophysiology of anosmia related to viral upper respiratory infections and the prognostic implications. Current evidence suggests that SARS-CoV-2-related anosmia may be a new viral syndrome specific to COVID-19 and can be mediated by intranasal inoculation of SARS-CoV-2 into the olfactory neural circuitry. The clinical course of neuroinvasion of SARS-CoV-2 is yet unclear, however an extended follow up of these patients to assess for neurological sequelae including encephalitis, cerebrovascular accidents and long-term neurodegenerative risk may be indicated.

Keywords: COVID-19; anosmia; coronavirus; olfaction; post-viral anosmia.

© The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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