COVID-19 School of Medicine

Learning How To Smell Again After COVID-19


Loss of smell has become a hallmark of COVID-19. Up to 80% of infected people experience it. While most people get their sense of smell back as they recover, some do not. And, as Will Stone reports, this phenomenon has triggered new interest and research studies in the field of smell.

WILL STONE, BYLINE: There are some smells that college student Bo Anderson (ph) really misses – the fresh cut grass of the baseball field before a game, his mother’s eggs and bacon mingling with pine on Christmas morning, even…

BO ANDERSON: As gross as my cat smells sometimes, you know, growing up with cats, I love them. So yeah, I miss that.

STONE: Anderson is a computer engineering major at Washington University in St. Louis. He got COVID-19 in the fall, and it was mild, mostly just headaches. A few days into quarantine, he woke up and couldn’t smell anything.

ANDERSON: I went in the bathroom and smelled my deodorant, and there was nothing. You know, I thought in the next week I was going to get it back, but it’s just never happened.

STONE: Which is why Anderson sits down at his kitchen table every day, opens a small jar of essential oils, brings it right up to his nose and sniffs…


STONE: …And sniffs…


STONE: …Until…

ANDERSON: For that one, I really couldn’t get a whole lot from it. But here and there, I’ll get a slight hint of oaky (ph) like tree bark.

STONE: That one was clove. Next, it’s eucalyptus.


ANDERSON: It makes my nose tingle.


STONE: Then lemon.


ANDERSON: Smells like sweaty socks mixed with like ice water with a lemon in it.

STONE: And finally, rose.


ANDERSON: I can get a nice hint of it.

STONE: While Anderson sniffs, he also looks at pictures of what he’s smelling. He does these smell retraining exercises every day and records the results. It’s for a study on post-COVID patients who’ve lost their sense of smell. The clinical term for that is anosmia. Dr. Jay Piccirillo is leading this study. He’s an ear, nose and throat specialist at Washington University School of Medicine.

JAY PICCIRILLO: Prior to COVID, doing research with anosmia, particularly viral-associated anosmia, was rather lonely.

STONE: Doctors have known for years that other viral infections can trigger loss of smell, but it was rare, so it was difficult to find enough patients to actually study. And key details were hard to pin down, like when the loss of smell started or what caused it. But all of this is changing with COVID-19.

PICCIRILLO: The magnitude of the problem, like complete loss of smell, the number of people affected and the number of people who have persistent problems, this is just unheard of.

STONE: Most people who lose their sense of smell from COVID-19 do recover within two months. But in a subset of patients – estimates are 5 to 10% – this problem persists. And because doing research was challenging before COVID, Piccirillo says there are few treatments and lots of questions even with smell retraining exercises.

PICCIRILLO: We don’t really have a good answer about, you know, how effective is it, and how effective is olfactory training above and beyond just doing nothing?

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