Olfactory Loss of Function as a Possible Symptom of COVID-19

To the Editor We read the recent articles by Eliezier et al¹ in JAMA Otolaryngology–Head and Neck Surgery and Mao et al² in JAMA Neurology, respectively, with great interest. Eliezier et al¹ describe the important case of a woman in her 40s who presented with an olfactory loss secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and Mao et al² describe neurologic manifestations of hospitalized patients with SARS-Cov-2 infection in China. They found that around 5% had a loss of their sense of smell and taste. As the coronavirus 2019 (COVID-19) pandemic is hitting both the US and Europe hard at the moment, symptoms of loss of sense of smell and taste, even in the absence of the other common symptoms of SARS-CoV-2 infection, need to be added to the list of primary screening symptoms for SARS-CoV-2 infection and should indicate the need for urgent COVID-19 testing and self-isolation. The US Centers for Disease Control has just added this to the symptoms related to COVID-19, but individual institutions may or may not be testing based on this symptom.³ In clinics in the UK, a number of health care professionals at the forefront of patient care during the COVID-19 pandemic have presented with loss of smell and taste. On testing, they were found positive for SARS-CoV-2 infection by quantitative polymerase chain reaction–based swab testing.⁴ The debate is ongoing regarding to what extent the loss of smell and taste in SARS-CoV-2 infection is caused by nasal congestion and edema in the upper portion of the nasal cavity or whether and how it is mediated by direct damage to olfactory neuroepithelial cells as a result of the infection. Experience by colleagues suggests that nasal SARS-CoV-2 infection does not appear to exhibit considerable nasal congestion or a runny nose⁵ and also favors a neurotropic and neuroinvasive pathogenesis, which may be site-specific to the olfactory system as has been shown for other coronaviruses previously⁵; however, the short time to recovery exhibited in some of these patients leaves the etiology unclear.

Loss of sense of smell and taste need to be added to the list of primary screening symptoms for SARS-CoV-2 infection in all countries and should indicate the need for urgent COVID-19 testing and self-isolation. Awareness and early recognition of these symptoms is particularly important for clinicians at the forefront of patient care during the COVID-19 pandemic.

Corresponding Author: Matt Lechner, MD, University College London Cancer Institute, 72 Huntley Street, London, WC1E 6DD, United Kingdom (m.lechner@ucl.ac.uk).

Published Online: July 16, 2020. doi:10.1001/jamaoto.2020.1589

Conflict of Interest Disclosures: Dr Philpott reported grants from the National Institute for Health Research, Rosetrees, Sir Jules Thorn Trust, Royal College of Surgeons, Bernice Bibby Trust, and personal fees from Sanofi-Genzyme outside the submitted work; and being a Trustee of the charity Fifth Sense that supports those afflicted with Smell and Taste Disorders. No other disclosures were reported.