Up to 1.6 Million People in the U.S. Have Long-Term Smell Loss Due to Covid-19

After six months of smell loss, the chance of recovery drops to less than 20 percent, and around 5 percent of all cases will result in permanent loss

An illustration of the anatomy of a person's profile with all the cavities, muscles and bones.
The coronavirus is suspected to attack specific cells in the nose that help olfactory nerves, which sense smell, operate.  Patrick J. Lynch

A loss of smell—called anosmia—can be one of the first symptoms of a Covid-19 infection; one study reports that between 30 and 80 percent of diagnosed folks experience some variation of anosmia. Taking a big whiff of perfume, food or wine and not smelling anything at all can be an odd, confusing sensation, but around 90 percent of people recover their sense of smell as soon as two weeks, reports Ed Cara for Gizmodo. However, some people are taking much longer to recover their smell. For others, it may never come back.

A new paper published this week in the journal JAMA Otolaryngology–Head & Neck Surgery estimates that up to 1.6 million people in the United States lost their sense of smell for at least six months as a result of a Covid-19 infection, reports Denise Mann for MSN.

"We've never really had a formal estimate made of how many people have been struggling with this," Sandeep Robert Datta, a neurobiologist at Harvard Medical School, tells Jen Christensen for CNN. "This is a really unusual event in terms of olfactory (smell) dysfunction and an unprecedented consequence of a pandemic that's never really been observed before."

Although other symptoms of long Covid can be more serious—such as brain fog, heart or lung damage and chronic fatigue—the long-term loss of smell isn't something to be overlooked. Folks with anosmia are twice as likely to experience hazards like inability to detect gas leaks, smoke or spoiled food, reports CNN.

Lyss Stern, a 47-year-old woman living in New York City, spoke to MSN about her experience. She lost her smell in March 2020, and it hasn't returned despite endless efforts, including vitamins, supplements, acupuncture and more.

"Yesterday, my husband asked, 'What's that smell?' and I had no idea," Stern tells MSN. "It was eggs boiling over in the kitchen that almost caught fire."

CNN reports that a loss of smell is also linked with higher rates of depression.

"It's really consequential to appetite and social relations, like people have lost their sense of smell may not be able to detect if they have body odor, and can impact diet too," John Hayes, director of the Sensory Evaluation Center at Penn State, tells CNN.

The likelihood patients with long-term anosmia recover their sense of smell isn’t very optimistic. After six months of smell loss, the chance of recovery drops to less than 20 percent; around 5 percent of all cases will result in permanent loss, reports Gizmodo.

"The long-term disease burden from this, we're literally going to be dealing with this for decades," Hayes tells CNN.

Why a Covid-19 infection affects smell is still unclear, and it's especially puzzling that the symptom can persist for months, reports MSN.

"We think that the virus attacks the supporting cells in the nose that help olfactory nerves do their job," Jay F. Piccirillo, an ear, nose and throat specialist at the Washington University School of Medicine in St. Louis, tells MSN. "People whose supporting cells get more infected and had a heavier load of the virus are more likely to have persistent loss of smell."

Understanding how the virus affects smell will help doctors figure out if and how it can be recovered. Some clinics offer smell therapy, which has been successful for some patients, but certainly not all, CNN reports.