Mouth Sores & COVID-19

Since the World Health Organization (WHO) declared COVID-19 a pandemic in March 2020, this infectious disease has killed over 6 million people worldwide.¹ COVID-19 is a viral infection caused by the SARS-CoV-2 coronavirus. 

The most common symptoms of COVID-19 are fever, chills, and sore throat. However, many other symptoms have been reported, including those affecting the oral cavity.

Mouth sores on the tongue (COVID tongue) are one of the most frequently encountered oral symptoms in people with COVID-19.⁷ Other oral symptoms include mouth lesions (sores) or ulcers on the gums, roof of the mouth, and soft palate.

This article explains the link between mouth sores and COVID-19, who’s at risk for COVID mouth sores, and how to treat them. 

How are Mouth Sores and COVID-19 Related?

Mouth sores are one of many oral manifestations seen in people with COVID-19. 

Long-term research studies are needed to establish a causal relationship between mouth sores and COVID-19. However, existing studies suggest an observed association between the two.^4,6-7

How Common are Mouth Sores With COVID-19?

More research is needed to determine how common mouth sores are in people with COVID-19. 

A 2020 study that included 666 people with COVID-19 in Spain reported that more than 25% experienced oral symptoms.⁴ 

These oral symptoms included:

• Oral ulcers
• Tongue swelling
• Gum inflammation
• Burning sensation
• Taste disturbances
• Red and white bumps on the tongue
• Painful lesions on the gums and mucous membranes of the mouth (oral mucosa)
• Patchy red and white spots on the surface of the tongue, similar to a geographic tongue

A 2021 study including 74 COVID-19 patients found that 78.4% had oral lesions. Canker sores (aphthous ulcers) were the most common lesion type. The tongue was the most common location.⁶

What is COVID Tongue?

Oral lesions on the tongue, known as COVID tongue, are the most common oral manifestations of COVID-19. 

COVID tongue usually appears as flat red patches of varying sizes surrounded by white borders. Similar clinical characteristics are seen in people with geographic tongues.

According to a 2022 case report of a patient who tested positive for SARS-CoV-2, oral symptoms that may accompany COVID tongue include⁷:

• Dry mouth
• Loss of taste
• Mouth ulcers
• Burning sensation
• White coating on the tongue’s surface

What Causes COVID Tongue?

The exact cause of COVID tongue is unclear. However, the scientific community has proposed possible causes, including:⁷

Cellular Changes

When the SARS-CoV-2 virus binds to the cells in the outer layer of your tongue (epithelium), it causes changes at the cellular level. This can lead to the oral mucosal lesions seen in COVID tongue.

Other Infections

The stress of being sick with COVID-19 and the medications you take to treat it can suppress your immune system. This may leave you vulnerable to other infections, including:

• Bacterial infections
• Fungal infections, such as oral thrush
• Other viral infections, such as the herpes simplex virus

Who is at Risk of Developing COVID Mouth Sores?

Populations more susceptible to chronic illnesses are at increased risk of developing oral diseases from COVID-19 infection.³

Common risk factors for developing oral complications from COVID-19 include: 

• Stress
• Poor diet
• Alcohol and tobacco use
• Substance misuse
• Behavioral health issues
• Domestic violence
• Poverty

Advanced age is also a risk factor. Older patients and those with a compromised immune system are at increased risk of developing more severe infections.

What is the Treatment for COVID Tongue and Mouth Sores?

There’s currently no established treatment for COVID tongue or mouth sores in people with COVID-19. 

Your dentist or healthcare provider may recommend one or more of the following treatments for oral manifestations of COVID-19:

• Antibacterial mouth rinses
• Antifungal or antiviral medications
• Nutritional supplements
• Dietary changes, such as avoiding spicy foods
• Corticosteroids to reduce the inflammatory response

It’s also important to practice good oral hygiene, get lots of rest, and drink plenty of water.

What is the Outlook for COVID Tongue and Mouth Sores?

More research is needed to determine the long-term oral health effects of COVID-19. Oral symptoms, including mouth sores and geographic tongue, usually resolve with treatment.

The amount of time it takes to recover from COVID tongue and mouth sores varies from person to person. One case study found that tongue-related symptoms in a patient with COVID-19 cleared up within one month.⁷ 

What are Other Symptoms of COVID-19?

Most people with COVID-19 will experience mild to moderate respiratory illness and recover without special treatment or hospital admission. People with mild symptoms who are otherwise healthy should manage them at home.

On average, it takes between five to six days from when someone is infected with COVID-19 for symptoms to show. However, it can take up to 14 days.

Common Symptoms

The most common symptoms of COVID-19 are: ¹

• Fever
• Dry cough
• Tiredness or fatigue

Less Common Symptoms

Less common symptoms of COVID-19 are: 

• Aches and pains
• Sore throat
• Diarrhea
• Conjunctivitis (pink eye)
• Headache
• Loss of taste or smell
• Skin lesions or rashes
• Discoloration of the fingers or toes

Serious Symptoms

Severe cases of COVID-19 may include the following symptoms: 

• Difficulty breathing or shortness of breath
• Chest pain or pressure
• Loss of speech or movement

If you have severe symptoms of COVID-19, seek medical attention immediately. Always call before going to your doctor or health facility. 

Summary

Mouth sores are an oral health problem that some people with COVID-19 develop. COVID tongue is the most common oral manifestation of the infection.

Tongue-related symptoms of COVID-19 include red patches with a white border, similar to those seen in geographic tongue, and a white coating. Other oral symptoms may include dry mouth, oral lesions, a burning sensation, and a loss of taste.

COVID tongue and mouth sores may be due to cellular changes from the SARS-CoV-2 viral infection or other bacterial, viral, or fungal infections caused by a weakened immune system.