What Is It, Causes, Signs, and More

Author: Lily Guo

Editors: Alyssa Haag, Józia McGowan, DO , Kelsey LaFayette, DNP, RN

Illustrator: Abbey Richard

Copyeditor: Sadia Zaman, MBBS, BSc

What is stomatitis?

Stomatitis refers to inflammation and redness of the oral mucosa that can lead to pain and difficulty talking, eating, and sleeping. Stomatitis can affect the inner cheeks, gums, inner lips, and tongue. The inflammation causes the formation of single or multiple painful mouth ulcers as well as white lesions. The two main types of stomatitis include herpes stomatitis (i.e., cold sore) and aphthous stomatitis (i.e., canker sore).

Dark complexion lips with inflamed areas of skin surrounding boarders of the lips and mouth.

Is stomatitis a sexually transmitted disease (STD)?

Stomatitis is not a sexually transmitted disease (STD). In some cases, stomatitis can be caused by the herpes simplex virus, which can be transmitted sexually. However, herpes simplex virus can also be transmitted through close contact like sharing eating utensils or kissing. 

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What causes stomatitis?

The causes of stomatitis depend on the specific subtype. Herpes stomatitis is commonly caused by the herpes simplex virus (HSV-1), whereas aphthous stomatitis is typically caused by poor oral hygiene or trauma to mucous membranes. Other causes of stomatitis include local infection (e.g., Candida albicans, bacteria); systemic diseases (e.g., Behçet disease, inflammatory bowel disease); nutritional deficiencies (e.g., vitamin B12 deficiency); physical or chemical irritants (e.g., oral care products), or an allergic reaction. Additionally, tobacco use, irritating foods, chemotherapy and radiation therapy can all increase the risk of developing stomatitis. Nonetheless, it is important to note that many causes of stomatitis are idiopathic or unknown.

What are the signs and symptoms of stomatitis?

The signs and symptoms of stomatitis include red patches, blisters, and swelling of the mouth. These symptoms may be accompanied by oral dysaesthesia, which is a burning sensation in the mouth, and recurring ulcers. The accompanying ulcers usually have a white or yellow layer with a red base and are typically inside the lips, cheek, gum, or on the tongue. The ulcerative lesions can also cause pain with eating, drinking, or swallowing, which may potentially lead to dehydration. Other symptoms of stomatitis include drooling, pain, and swelling of the gums

How is stomatitis diagnosed?

Stomatitis can be diagnosed through a thorough physical examination by a clinician. They may take note of the severity of pain and presence of triggers, such as specific foods, toothpaste, or drugs. The clinician may assess for potential underlying causes, such as tobacco use, presence of sexually transmitted infections, or immune system compromise that may predispose the person to infection. If the symptoms of stomatitis are recurrent, aphthous stomatitis and herpes stomatitis are typically the cause. Having a history of diabetes or HIV infection, or using antibiotics recently should increase suspicion of a Candida infection as cause of stomatitis. If those with acute stomatitis experience no signs, symptoms, or risk factors for systemic illness, they typically require no testing. If symptoms of stomatitis are prolonged and severe, testing can be performed to confirm the cause. Subsequent testing includes bacterial and viral cultures, laboratory tests (e.g., complete blood count, serum iron, ferritin, vitamin B12, folate, zinc, and tissue transglutaminase antibody for celiac disease) are conducted. If there is no obvious etiology and the lesions are persistent, a biopsy can be conducted at the periphery of normal and abnormal tissue. 

How is stomatitis treated?

Treatment for stomatitis depends on the underlying cause. For cases of herpes stomatitis, antiviral medications (e.g., acyclovir, valacyclovir) may be administered. Additionally, over-the-counter ointment (e.g., docosanol) can assist in shortening the length of infection. Over-the-counter medications, such as acetaminophen, can be used to reduce the pain associated with stomatitis. Aphthous stomatitis is rarely severe and treatment may not be necessary, especially if it clears on its own within 1-2 weeks. 

For large and persistent sores, mouth rinses containing chlorhexidine, an antimicrobial; dexamethasone, which can reduce inflammation; or lidocaine for pain relief, can be prescribed by a clinician. Topical creams containing benzocaine, fluocinonide, and hydrogen peroxide can also be used to relieve pain and accelerate healing. Lastly, for uncommonly severe cases of aphthous stomatitis, chemical cauterization (i.e., burning or destruction of tissue) may be indicated. Debacterol and silver nitrate are two chemicals used for cautery of sores in the mouth, and can reduce healing time. In all cases, since dehydration is a risk, the individual should be encouraged to drink more fluids, specifically water. Individuals should also be encouraged to reduce the intake of acidic foods and beverages to reduce further irritation.

What are the most important facts to know about stomatitis?

Stomatitis refers to inflammation of the oral mucosa, which presents with ulcers that can cause pain and difficulty drinking and eating. Ulcer(s) can be present on the inner lips and cheeks, on the gums, or on the tongue and are caused by infection, irritants, trauma, or allergic reactions. A common cause of herpes stomatitis, a subtype of stomatitis, is herpes simplex virus. Another common type of stomatitis is apthous stomatitis, or a canker sore, which is caused by poor oral hygiene or trauma to the mucous membranes. Diagnosis involves history taking, physical exam, and if necessary, laboratory testing to determine the cause. Treatments for stomatitis include oral rinses, topical ointments, antivirals if the etiology is viral, and anti-inflammatory medication to reduce the swelling and pain. 

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Related links

Herpes simplex virus
Aphthous ulcers
Herpesvirus medications

Resources for research and reference

Gonsalves, W. C., Chi, A. C., & Neville, B. W. (2007, February 15). Common Oral Lesions: Part I. Superficial Mucosal Lesions. In American Family Physician. Retrieved November 29, 2021 from 

Hennessy, B. J. (2021, November 17). Stomatitis - dental disorders. In Merck Manuals Professional Edition. Retrieved November 29, 2021 from 

Mayo Clinic. (2018, April 3). Canker sore. In Mayo Clinic. Retrieved November 29, 2021 from 

Mayo Clinic. (2020, June 17). Cold sore. In Mayo Clinic. Retrieved November 29, 2021 from 

Mayo Clinic Laboratories. (2022). Tissue Transglutaminase Antibody, IgA, Serum. In Mayo Clinic Laboratories. Retrieved January 9, 2022, from 

Mortazavi, H., Safi, Y., Baharvand, M., Jafari, S., Anbari, F., & Rahmani, S. (2019). Oral White Lesions: An Updated Clinical Diagnostic Decision Tree. Dentistry Journal, 7(1), 15. DOI: 10.3390/dj7010015

Porter, S., Mercadente, V., & Fedele, S. (2018). Oral manifestations of systemic disease. BDJ Team 5, 18012. DOI: 10.1038/bdjteam.2018.12

Tulane University. (March 16, 2020). STI vs. STD: Key Differences & Resources for Students. In Tulane University Blog. Retrieved January 9, 2022 from 

Volkov, I., Rudoy, I., Abu-Rabia, U., Masalha, T., & Masalha, R. (2005). Case report: Recurrent aphthous stomatitis responds to vitamin B12 treatment. Canadian family physician Medecin de famille canadien, 51(6), 844–845.