Mar 6, 2021 - Health

COVID-19 drives smell loss awareness, research

A health worker carries out an olfactory test to monitor smell loss.
A health worker carries out an olfactory test outside Buenos Aires. Photo: Alejandro Pagni/AFP via Getty Images

The pandemic has thrust a relatively unknown ailment, anosmia — or smell loss — into the international spotlight.

Why it matters: Researchers hope smell testing becomes as standard as the annual flu shot, helping to detect early signs of neurodegenerative diseases like Alzheimer’s and Parkinson’s.

  • "Loss of smell is associated with so many different health conditions," olfactory researcher Pamela Dalton told Axios. "It’s something we should be checking."

The big picture: Severe or complete smell loss — which impacts roughly 3% of the 40+ U.S. population — has devastating effects, making sufferers feel ostracized, isolated in social settings, and unable to fully taste or enjoy food.

  • There are few tools to diagnose and treat it.

Now a growing group of people who haven't recovered their sense of smell months after having COVID are joining these ranks.

  • Studies suggest that a majority of people who get COVID-19 experience smell loss. For most of them, it's temporary. But at least 5% seem to have long-term loss.
Chart: Axios Visuals
Chart: Axios Visuals
  • This has public health and safety implications ranging from depression to not being able to sense danger like fire.

What’s next: Innovation in the smell space could make smell testing more accessible, identify treatments and improve quality of life for a significant part of the population.

  • While smell testing currently exists, it's not widely used and can be expensive, employing dozens of odors, Dalton, who works at Monell Chemical Senses Center, told Axios.
  • The Center, based in Philadelphia, received an NIH grant at the end of last year to research the effectiveness of a "lift and sniff" test that has just one odor and could be used to rapidly detect COVID.
  • Another study is looking into at-home scratch-and-sniff tests.

Yes, but: There are concerns about the limitations of diagnostic smell tests, as the New York Times has reported.

What's next: Cyrano Therapeutics, a Washington, D.C.-based medicine company, is researching a nasal spray for anosmia, with randomized trials set to start next year.

  • Clinical trials by Washington University School of Medicine aim to test multiple therapies for COVID-related smell loss: a nasal rinse and a specific type of smell training (regularly inhaling certain scents) that incorporates visuals and "patient-preferred scents" rather than pre-determined odors.
Go deeper