COVID-19, caused by SARS-CoV-2, is primarily known for respiratory symptoms. However, like many viral infections, it can also produce symptoms affecting the mouth and tongue. The appearance of bumps, lesions, or other changes on the tongue has been reported in patients diagnosed with SARS-CoV-2. This phenomenon, sometimes informally called “COVID tongue,” shows a connection between the virus and these oral manifestations.
Research Linking COVID-19 to Oral Manifestations
Early in the pandemic, researchers began documenting skin and mucosal changes in people with COVID-19. Studies from various countries, including a notable report from a field hospital in Madrid, Spain, identified oral lesions in a subset of patients positive for SARS-CoV-2. This showed the virus or the resulting illness was associated with changes in the oral cavity.
The Madrid study, involving hundreds of patients, reported that around 25% had some form of oral cavity finding. Specific tongue issues, such as transient lingual papillitis, were noted in a significant percentage of patients. These oral symptoms appeared during the acute phase of the infection, often within the first two weeks of the illness.
Subsequent systematic reviews confirmed that oral manifestations are a genuine, though less common, part of the disease presentation. While loss of taste (dysgeusia) and dry mouth (xerostomia) are more frequently reported, tongue lesions and bumps are also documented. These observations established a clear link between SARS-CoV-2 infection and various changes on the surface of the tongue.
Description of Common Tongue Symptoms
The term “COVID tongue” encompasses several appearances, including bumps, lesions, or patches. One common finding is transient lingual papillitis, where the small, normal bumps on the tongue called papillae become inflamed and swollen. These inflamed papillae appear as prominent, painful red or white bumps, often located along the sides or tip of the tongue.
Another manifestation is glossitis with patchy depapillation, also known as geographic tongue. This condition involves the loss of papillae in certain areas, resulting in smooth, red patches bordered by a slightly raised white line. The patches can appear to “migrate” across the tongue’s surface over time, creating a map-like appearance.
Other reported symptoms include fissured tongue, which involves deep grooves or cracks on the surface, and aphthous-like lesions, which are painful, small, round ulcers. The tongue may also become swollen or inflamed, a condition known as glossitis, which sometimes results in indentations along the sides from pressing against the teeth. These varied presentations highlight that the virus’s effect on the tongue is a spectrum of inflammatory responses.
Biological Reasons for Oral Involvement
The tongue’s involvement in COVID-19 results from a combination of direct viral activity and the body’s systemic immune response. The SARS-CoV-2 virus uses the Angiotensin-Converting Enzyme 2 (ACE2) receptor to enter human cells. ACE2 receptors are highly expressed on the epithelial cells of the oral mucosa, particularly on the tongue and in the salivary glands.
This high concentration of entry points suggests the virus may directly infect and damage the cells of the tongue and taste buds, leading to inflammation, swelling, and lesions. Direct viral damage to taste bud cells, which also express ACE2, is a proposed mechanism for the associated loss of taste.
Beyond direct infection, widespread systemic inflammation plays a significant role. Severe COVID-19 is characterized by a hyper-inflammatory state, sometimes called a cytokine storm, where the immune system releases an excessive amount of inflammatory molecules. These inflammatory mediators, such as Interleukin-6, circulate throughout the body and can damage blood vessels and tissues, including those in the oral cavity. Indirect factors also contribute to oral changes, such as dry mouth caused by viral infection of the salivary glands, or immunosuppression resulting from the illness itself, which can lead to opportunistic infections like oral thrush.
When to Seek Medical Guidance
For most people, any tongue changes experienced during a viral illness, including COVID-19, are temporary and resolve as the infection clears. If the bumps or lesions are mild and associated with other COVID-19 symptoms, symptomatic relief such as over-the-counter pain relievers or anti-inflammatory mouth rinses is often sufficient.
Seek medical advice if the symptoms on the tongue persist for longer than two weeks after the main viral symptoms have subsided. Immediate medical consultation is necessary if the tongue swelling is severe, causes difficulty breathing or swallowing, or is accompanied by signs of a secondary infection, such as increasing redness, pus, or fever. Many other factors, including nutritional deficiencies, stress, certain medications, or other underlying conditions, can cause similar tongue bumps, meaning a persistent symptom warrants a professional diagnosis to rule out other causes.