ST. LOUIS — Elizabeth Tesson remembers the exact moment she lost her sense of smell, the day after she tested positive for COVID-19.
“I got a very odd feeling in my nose, like a burning sensation in my sinuses and along my cheeks,” said Tesson, who lives in St. Louis County. “About an hour and a half later, I went to take a shower, and I couldn’t smell the soap.”
That was almost five months ago — and her sense of smell still hasn’t returned.
Loss of smell, or anosmia, is one of the telltale signs of COVID-19, affecting up to 80% of patients by some estimates. Nearly a year into the pandemic, scientists are scrambling to understand how the coronavirus damages the sensory system and if there’s a way to reverse it. Though there is no cure, an experimental therapy currently being tested at Washington University has given some patients hope.
How exactly the virus causes smell loss is still somewhat of a mystery. Most people recover their sense of smell within weeks, but some, like Tesson, are still unable to smell months later.
At first, scientists thought the virus might be attacking neurons inside the nose responsible for detecting and transmitting smells to the brain. Instead, the virus appears to primarily affect cells surrounding the nerve that are able to regenerate more quickly, perhaps explaining why most patients recover their sense of smell.
But given the sheer number of COVID-19 cases nationwide, Jay Piccirillo, a Washington University professor of otolaryngology, worries about a “coming tidal wave” of long-term smell loss.
About 1 in 10 people will experience persistent disruptions in smell six months after recovering from COVID-19, Piccirillo said, generating “a number of people with anosmia that we’ve never really experienced.”
Though Piccirillo has studied viral-related smell loss for years, his research team has struggled to recruit enough patients — and those who signed up were often unsure when they had lost their sense of smell. “All of that faded away with this COVID pandemic,” he said. “For once in my professional lifetime, people knew exactly when they lost their sense of smell, and we had a large number of patients.”
His research team is among the first in the country to test whether an existing therapy known as “smell training” may help COVID-19 patients regain the ability to smell. As part of the 12-week study, patients sniff certain essential oils, like peppermint and lemon, twice a day, sometimes while looking at photos associated with the smells.
The Wash U research team plans to mail about 250 smell training kits to patients nationwide who have recovered from COVID-19 but have not regained their sense of smell or taste.
Maria Turturici enrolled in the clinical trial in February. The Connecticut nurse lost her sense of smell and taste in June after contracting the coronavirus, and since then, she said, odors are strangely distorted.
Scents that she used to enjoy, like vanilla ice cream or campfire smoke, now smell “worse than trash” — symptoms of a smell disorder known as parosmia. But mostly, Turturici said, everything just smells and tastes like cardboard.
“It’s really sad because I was the biggest food snob,” she said. “Early on, I literally had to remind myself to eat. Now, I’ll eat microwavable cauliflower by the bag because I can’t smell or taste it.”
It’s been hard to explain the experience to other people, Turturici added, so she has mostly kept it to herself.
“How have you all gotten your friends/family to take you seriously?” one person wrote. “It’s been 6 months for me of essentially no smell or taste, and no one around seems to understand. If only they knew how depressing it was.”
Elizabeth Tesson, who also enrolled in the Wash U smell training study, has been keeping a list of smells that she misses most: fresh-cut grass, rainstorms, suntan lotion.
Since beginning the study in early February, Tesson has been seeing small signs of improvement. On a recent morning, she got a surprise when she unscrewed the lid of her husband’s thermos.
“I thought there was coffee in there, but it was actually his water cup,” Tesson said. “And all of the sudden, I got a whiff of lemon. I looked down and I thought, ‘Holy cow, I actually smelled the lemon.’”
Feeling encouraged, she jotted down “Seems like progress this morning!” in the journal the research team asked her to keep.
“I thought it would probably take months to smell anything at all,” Tesson said. “Maybe in the coming weeks, when we’re cooking dinner, I’ll actually be able to smell something. That would be nice.”
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For more information on the Washington University smell training study, email firstname.lastname@example.org or submit an eligibility survey.