What Is the Connection Between Mouth Sores and COVID-19?

March 29, 2022

The oral cavity can be home to different types of ulcers, including canker sores, sores from oral thrush, and non-specific sores, meaning there’s no specific cause that can be found. In cases of non-specific mouth sores, the underlying cause could be from an impaired immune system or allergic reaction.

For some people, a COVID-19 infection can cause mouth ulcers. The virus can also increase your risk for oral thrush and canker sores, especially since dry mouth is a common symptom in the majority of patients. COVID-19 has even been linked to gingivitis (gum inflammation) as a result of its impact on the immune system [1].

What exactly is the connection between mouth sores and COVID-19? Let’s take a closer look.

Older Patients and More Severe Cases More at Risk for Oral Lesions

Oral lesions such as ulcers have been found equally in male and female patients. However, older patients were more likely to have oral lesions, as were patients who had more severe cases of COVID-19 [2]. Research shows that stress, impaired immune function, lack of oral hygiene, and inflammation were all involved in the likelihood and formation of oral lesions in COVID-19 patients.

Oral Thrush May Be a Symptom of COVID-19

Many patients report dry mouth as a symptom of COVID-19. In fact, it’s one of the first symptoms to emerge in many cases. However, research also shows that patients with the virus can have oral lesions, a burning sensation in their mouth, loss of taste, and an oral thrush infection [3].

Oral thrush happens when a natural yeast that lives in the mouth, Candida albicans, gets out of control. The result is an oral infection with lesions, redness, and burning in the mouth. Dry mouth is a risk factor for oral thrush, but so is a weakened immune system. Patients with COVID-19 may be more at risk for oral thrush lesions and infection for these reasons.

Mouth Sores Are Associated With Loss of Taste

In the majority of patients with oral lesions, a loss of taste and smell coexisted with the mouth sores [4]. Mouth sores in COVID-19 patients have been observed to be both mild, with lesions being similar to canker sores, and more severe ulcers in older patients and patients who were immunocompromised.

What’s the Bottom Line?

Although COVID-19 is suspected to be the cause of mouth lesions that coexist with an acute infection of the virus, research is still ongoing [5]. The good news is that lesions typically go away on their own once the patient recovers.

However, if you have oral thrush or dry mouth, you will need to follow up with your dentist to ensure these conditions are treated, as they can delay healing of oral lesions and cause additional oral health issues. Researchers of mouth sores in COVID cases highlight the importance of oral care when it comes to staying healthy and reducing complications of COVID-19.