The British Association of Otorhinolaryngology (ENT UK) raised the issue in a statement on Friday, citing the “rapidly growing number of reports” of patients with little to no other symptoms losing their sense of smell. ENT UK said it could be an important marker of the infection for which health-care workers should consider asking people to self-isolate.
The ENT UK — made up of leading British ear, nose and throat doctors — cites compiled reports from countries like Germany and South Korea, where patients presented anosmia as their “major presenting symptom in otherwise mild cases,” meaning without coughing and high fever.
The most common symptoms of COVID-19 include fever, dry cough and tiredness. Anosmia is the loss of the sense of smell, either totally or partially, while ageusia is the loss of taste functions of the tongue.
The researchers called for people experiencing the loss of smell or taste to self-isolate, saying the reports suggest they could be “hidden carriers” capable of facilitating the spread of the virus.
“If anosmia was added to the current symptom criteria used to trigger quarantine, and any adult with anosmia but no other symptoms was asked to self isolate for seven days, we might potentially be able to reduce the number of otherwise asymptomatic individuals who continue to act as vectors, not realizing the need to self-isolate,” their statement reads.
A diminished sense of taste and smell can be symptomatic of a wide variety of illnesses, respiratory or otherwise, according to Dr. Isaac Bogoch, an infectious disease specialist based out of Toronto General Hospital.
“I doubt this is a very specific feature of COVID-19. It might be a feature, but likely not a uniquely distinctive one compared to other infections,” he said.
“I don’t think anyone would be surprised if people with COVID-19 have it, but think back to any time you’ve had a respiratory tract infection, regardless of how sick you were, it’s possible you had a temporary loss or reduction in your smell or taste during the course of that infection.”
Bogoch said in his experience, it’s rare medical practitioners even ask patients whether they’re experiencing a loss of these senses, which might also be part of the problem.
“It’s not like a diagnosis really hinges on that one symptom.
“People are going into the doctor’s with symptoms of a respiratory infection. You don’t show up to the doctor’s office and we say, ‘How is your sense of smell?’ And if someone says it’s decreased, that doctor isn’t going to say, ‘A-ha! It can only be one thing!’ If it’s along for the ride, so be it, but it’s not definitive.”
He was wary of ENT UK’s suggestion that people with no other symptoms could be hidden carriers but acknowledged that a full clinical study integrating this symptom would provide clarity.
In the meantime, he said while it’s not unreasonable that people with COVID-19 could see a decrease in their sense of smell, on the scale of importance in symptoms, anosmia is “minimal.”
“It’s a common symptom in many infections. It’s usually extremely mild,” he said. “If people truly have no other symptoms at all, I don’t think it would be wise to start rushing to testing centres.”
Dr. Faheem Younus, who specializes in infectious diseases at the University of Maryland, felt similarly to Bogoch.
Younus has been using his Twitter account to bust myths related to COVID-19 since the outbreak began. He described the loss of taste and/or smell as a “non-specific symptom.”
“It’s common to temporarily lose one’s sense of smell with many viral infections/allergies,” Younus tweeted Sunday.
“It’s a non-specific symptom that may or may not happen with COVID.”
However, those diagnosed with the infection are describing their experience with the symptom online, including Utah Jazz player Rudy Gobert.
Gobert, whose positive test triggered a shutdown of the NBA, tweeted that he had noticed those senses diminished.
“Just to give you guys an update, loss of smell and taste is definitely one of the symptoms, haven’t been able to smell anything for the last 4 days. Anyone experiencing the same thing?” he tweeted.
Tamara Elliott, an HIV and sexual health doctor based in the U.K. who tested positive for COVID-19, said that while her illness so far feels mild, she’s experiencing anosmia and ageusia.
Bogoch was cautious: “These reports are only just emerging.”
“We have to remember that this is the kind of symptom that’s common in many infections.”
— with files from Reuters