BOSTON, 24 April 2020:
A sudden loss of smell and/or taste could be an early symptom of Covid-19 infection, long before other symptoms like dry cough or fever manifest, according to the US Centers for Disease Control and Prevention (CDC).
CDC recently added this new symptom to its coronavirus infection alert page, warning that other symptoms which may appear 2-14 days after exposure to the virus include shortness of breath or difficulty breathing, chills, repeated shaking with chills, muscle pain, headache and sore throat.
British Rhinological Society president Dr Claire Hopkins said: “Physicians evaluating patients with acute-onset loss of smell or taste, particularly in the context of a patent nasal airway, should have a high index of suspicion for concomitant SARS-CoV-2 infection.”
University of California San Diego head and neck surgeon Dr Carol H. Yan also thinks sudden smell and taste loss seem to be fairly specific markers of Covid-19. “If you have smell and taste loss, you are more than 10 times more likely to have Covid-19 infection than other causes of infection. The most common first sign of a Covid-19 infection remains fever, but fatigue and loss of smell and taste follow as other very common initial symptoms.”
Based on Dr Yan’s report and other case reports, the UC San Diego Health system is now asking all callers to its Covid-19 hotlines, and all visitors and staff, if they’ve had a sudden loss of taste or smell in the last few weeks, she added.
Writing in the Laryngoscope Investigative Otolaryngology journal, University of Cincinnati’s Dr Ahmad R. Sedaghat noted a sudden loss of sense of smell wouldn’t necessarily lead people to think they have Covid-19, particularly if they remain asymptomatic, so “these individuals could continue business as usual and spread the disease as a carrier”.
Despite rising number of reports of this being an important red flag for Covid-19, the World Health Organisation has not listed loss of smell or taste as potential symptoms of SARS-CoV-2 infection.
As such, a survey is being conducted by the Global Consortium of Chemosensory Researchers – involving over 600 clinicians, neurobiologists, data scientists, cognitive scientists, sensory researchers, and technicians from 50 countries – to collect and analyse the feedback received. Malaysia is one of the countries involved in this survey.
In the meantime, there’s a simple test you can already do at home or in the office – using peanut butter and vinegar – said Dana Small, 48, a Victoria-born psychologist and neuroscientist who teaches psychology and psychiatry at Yale University.
If the peanut butter scent fades, but the vinegar continues to trigger the nasal passages – as it’s an irritant – it’s a likely sign that someone’s sense of smell is deteriorating, and should immediately seek to undergo testing for Covid-19.