What Is 'COVID Tongue'?

Reports are surfacing of a possible new symptom of COVID-19 related to your mouth. Features of "COVID tongue" include tongue discoloration, enlargement, mouth ulcers, and more.

The reports initially came from England where Tim Spector, a researcher at King’s College London, was tracking COVID-19 symptoms in British patients. He began noticing an increasing number of patients with tongue discoloration, enlargement, and other mouth problems.

Is this a new indicator of COVID-19 infection? Verywell asked experts whether COVID tongue is real and how worried the public should be.

Is "COVID Tongue" Real?

Susannah Hills, MD, an airway surgeon and assistant professor of Otolaryngology at New York-Presbyterian/Columbia University, tells Verywell that she's not entirely convinced that COVID tongue is a real diagnostic sign.

“Tim Spector recently reported COVID tongue as a ‘thing’ but said it affects less than one in 100 people in their research database of COVID cases," says Hills. In an interview with USA Today, Spector said that one in five people will present with unofficial symptoms such as discolored or swollen tongues.

Hills says that in her mind, "it’s really difficult to make an association between a disease and a symptom that’s showing up that infrequently.”

Peter Gulick, DO, professor of medicine and infectious disease expert at Michigan State University College of Osteopathic Medicine, tells Verywell that he thinks it's still too early to tell if COVID tongue is real—but he does think it's possible.

Gulick points out that for safety reasons, healthcare providers have reduced the number of exams they perform that require a patient to take their mask off.

“Maybe things weren’t seen because nobody did the exams, and maybe [patients] dismissed it as poor hygiene rather than looking at it specifically as a COVID issue,” Gulick says. “And if [doctors are] doing a lot of virtual screenings, then we never see the patient beyond the television monitor, so you can’t really see the mouth either.”

Preliminary Studies Link Mouth Problems to COVID

While the evidence is limited, there has been some research linking oral problems to the COVID-19 virus that first appeared in Wuhan, China.

• In September 2020, a study in the British Journal of Dermatology discovered that of 666 adults who tested positive for COVID-19, 25.7% also experienced oral problems, including tongue inflammation, mouth ulcers, patchy tongues, and swelling of the mouth.
• Early observations in a July JAMA Dermatology study found mouth rashes in 6 of 21 patients with COVID-19.
• A report in the journal Oral Diseases examined two patients who tested positive for COVID-19 and developed mouth ulcers.
• A July 2020 study published in Integrative Medicine Research found that people with COVID-19 had greasier and more tender tongues. Tongue discoloration was also observed in patients with mild to moderate infections, who had a light red tongue with a white coating. Severe infections were associated with purple and yellow tongues.

Possible Causes of COVID Mouth Problems

It’s too early to tell if there are mouth and tongue problems related to COVID-19 infections. However, there are several mechanisms that could explain the link.

Brain and Nerve Effects

Hills suggests that since there is evidence of the COVID-19 virus affecting the brain, it could also potentially injure or hijack the nerves that control the tongue.

COVID-19 Treatments

There’s also a chance that COVID-19 treatments could be indirectly causing mouth problems. “For patients who aren’t able to eat or drink normally because of the illness, or for those who are in the hospital receiving breathing support or even requiring a breathing tube or a feeding tube, there could also be injury or irritation of the tongue tissues from trauma, dry air, or even nutritional deficits (like B12) from not being able to eat well," Hills says.

Dry Mouth

The ACE2 receptors targeted by the COVID-19 virus are present in the lungs and several mouth areas, including the salivary glands. Gulick says that a COVID-19 infection in the salivary gland could decrease secretion in the mouth and cause dry mouth. Having a dry mouth, in turn, could prompt other oral issues that have also been linked to COVID-19, such as teeth decay and teeth that have fallen out.

Thrush

Gulick also says that reports of "furry tongues" could be from steroids such as dexamethasone that cause an immunosuppressed state, which can make a person susceptible to oral thrush.

Other Viral Infections

COVID-19 increases inflammation, which may indirectly activate other viral infections such as the herpes simplex virus, which can cause mouth ulcers.

A case report published last June documented a similar scenario. One patient tested positive for COVID-19 and soon after experienced a series of conditions, including a herpes infection, oral thrush, and a geographic tongue.

Why Good Oral Health Matters

Your mouth is teeming with bacteria. Keeping it as clean as possible is essential to mitigate ulcer formation and any other potentially COVID-related inflammation. At the very least, if there was an acute inflammatory response, Gulick says that good oral health won’t make the problem any worse.

As doctors and researchers learn more about COVID tongue, there are some things that you can do. For one, stay abreast of any changes to your oral health and if you notice anything unusual, tell your healthcare provider.

If you think you have COVID-19, whether or not you have any mouth-related symptoms, the best thing you can do is get tested. “If it was me and I didn’t know why my mouth was like this, I would go and do a COVID test just to cover all the bases," Gulick says.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.