Most of us are now familiar with the more common symptoms of COVID-19, including, but not limited to: 

• Fever or chills
• Cough
• Shortness of breath or difficulty breathing
• Fatigue
• Muscle or body aches
• Headache
• New loss of taste or smell
• Sore throat
• Congestion or runny nose
• Nausea or vomiting
• Diarrhea

However, we’re now learning that changes to another part of the body may also indicate COVID-19: the tongue.

Not Just the Fingers and Toes, But Possibly the Tongue

Skin rash and discolored fingers or toes, known as “COVID fingers and toes,”  is a less common symptom of COVID-19 of which experts have cautioned the public to be aware. Now, an emerging new symptom has come to experts’ attention. The condition is called “COVID tongue” and it is characterized by changes to the mouth or tongue from COVID-19.

What We Know about COVID Tongue:

Many people with COVID-19 have indicated that their tongue was white and patchy. 

These observations are supported by a recent review of more than 17 studies, in which two dentists independently examined over 170 confirmed cases of “oral manifestations of COVID-19” in people ranging from 9-90 years of age.

• Dry mouth was found to be the most common oral problem, followed by loss of taste and fungal infection (thrush) that can appear as white blotches.
• Changes in tongue sensation and tongue ulceration, pain while chewing, mouth swelling, and ulceration of the inner mouth surface and lips were also reported.

The cause of COVID tongue and COVID-related mouth changes is unknown, but there are several possibilities:

• A direct effect of coronavirus infection
• A general immune response to the virus
• Increased vulnerability to oral infection (thrush) with COVID-19

How widespread is COVID tongue? A 2020 study from Spain found that about 25% of people hospitalized with COVID-19 had tongue and mouth abnormalities. Though it isn’t yet known how common COVID tongue is in the general population, it isn’t believed to be common in mild COVID-19.

Other important notes regarding COVID tongue:

• We don’t yet know the reliability of COVID tongue as a disease indicator.
• These oral conditions can have other causes; it’s very common for mouth ulcers to appear, and there are many illnesses and infections that can cause tongue changes.
• It’s not yet known whether COVID tongue can stand alone as a COVID-19 symptom.
• It’s also not yet known whether there’s a point in COVID-19 that COVID tongue tends to appear.

The ZOE COVID Study

The ZOE COVID Study is a non-profit initiative aimed at furthering our understanding of COVID-19. Launched in March 2020, the ongoing study uses an app developed by the health science company ZOE that allows the general public to contribute to COVID-19 research, with data analysis performed by King’s College London. 

Now with over four million users worldwide, the study is the most extensive COVID-19 research program in the world and is led by ZOE co-founder Tim Spector, a professor of genetic epidemiology at King’s College London.

Among other important uses, the app has helped researchers identify or confirm many COVID-19 symptoms, like loss of smell, skin rash, and sudden confusion. Users are also asked about any unusual symptoms, which is how COVID tongue appeared on the radar.

*ZOE COVID Study. (2021, March 10). What is ‘covid tongue’ and what does it look like? https://covid.joinzoe.com/post/covid-tongue

Much about the novel coronavirus, i.e., COVID-19, is still not fully understood. As research progresses and our knowledge of the virus increases, information can change rapidly. We strive to update all of our articles as quickly as possible, but there may occasionally be some lag between scientific developments and our revisions.