Millions of people who lost their ability to taste or smell after a COVID-19 infection have had their senses return, according to a recent study.
However, the same can’t be said for millions of others in the U.S., a study published June 2 in the Laryngoscope, a peer-reviewed medical journal suggests.
Of 35.8 million U.S. patients diagnosed with COVID-19 in 2021, 60.5 percent reported a loss of smell, while 58.2 percent experienced a loss of taste, according to the work involving researchers at Massachusetts Eye and Ear, a Harvard University teaching hospital based in Boston.
While most individuals studied completely regained their lost senses, smell didn’t fully return for 24.1 percent of patients and 3.7 percent didn’t recover that sense at all, the study found. Meanwhile, 20.6 percent didn’t fully recover their sense of taste and 2.6 percent haven’t regained that sense.
This was estimated to be about 6 million and 4.8 million patients with their senses of smell or taste, respectively, still lacking, study author Dr. Neil Bhattacharyya, a professor of otolaryngology at Mass Eye and Ear, confirmed in a statement to McClatchy.
The study also found the severity of a person’s COVID-19 infection was linked to a lower likelihood of regaining senses.
“We wanted to quantify the national impact of smell disorders resulting from COVID,” Bhattacharyya said in a news release on the research.
Bhattacharyya took part in the study after witnessing a patient who lost his sense of smell be unable to eat. As a result, the patient lost 50 pounds and had depression, according to the release.
“When you hear about COVID-related smell loss, you think most people get it back and are fine,” he said. “But there is a substantial number of people who don’t recover it.”
The findings are based on data from 29,696 U.S. adults included in the 2021 National Health Interview Survey.
The study focused on data from 2021 only, which was noted as a limitation of the work. This means if a patient had regained smell or taste after 2021, it was not accounted for.
Are there any remedies?
There’s no standard course of treatment for a loss of taste or smell following a COVID-19 infection, according to the researchers, who emphasize more research is needed to gather data for evidence-based treatments.
The researchers note experts have recommended nasal steroid sprays such as fluticasone for sensory loss.
A small study published Jan. 16, 2021 in the American Journal of Otolaryngology found fluticasone nasal sprays “significantly improved” smell function in patients whose sense was affected by COVID-19.
The same work also examined if triamcinolone dental paste, a topical steroid used to treat mouth sores, had an effect on patients experiencing a disturbance in their taste capabilities. Similarly to how fluticasone benefited those with smell issues, the dental paste had a positive effect on patients with issues tasting after becoming infected with the virus.
This study involved 120 patients and was done from June to November 2020.
In the current study, the researchers also say experts have recommended sensory training.
For smell loss, Dr. Thomas Hummel created a technique called smell retraining therapy at the University of Dresden in Germany in 2009, according to ENT Health. It was developed for those who lost their sense of smell after a viral infection or head injury.
It involves presenting a patient with varying scents — such as floral, citrus and spicy — to help stimulate olfactory senses and memory of smell, according to ENT Health.
In regards to other possible treatments, researchers in the current study wrote it “is unclear whether oral steroids or other therapies (vitamin A drops, omega-3 supplements) are of benefit.”
Pain injections used as a treatment method
At the Cleveland Clinic, anesthesiologist and pain medicine specialists have been treating patients with reported smell and taste dysfunction post-COVID-19. They’ve been doing so with a treatment used to help patients experiencing pain.
The method, a stellate ganglion block, involves an injection into nerves at the bottom of a person’s neck above the collarbone, according to an article published by the Cleveland Clinic.
“Since April 2022, we’ve had success when treating some of our patients for their altered taste and smell,” Dr. Christina Shin, who works at the Cleveland Clinic, said in a statement in the article. “We need further research to better understand how effective this injection is for long COVID treatment, why it works, and for whom it works.”
In the current study, researchers concluded that vaccines and medications such as Paxlovid, which reduce COVID-19’s “overall disease burden,” may be crucial in helping prevent sensory loss associated with the coronavirus.
“The value of this study is that we are highlighting a group of people who have been a bit neglected,” Bhattacharyya said. “Losing your sense of smell or taste isn’t as benign as you may think. It can lead to decreased eating for pleasure and, in more extreme cases, it can lead to depression and weight loss.”