What Is Stomatitis?

Inflammation of the Mouth

Stomatitis is inflammation of the mucosal tissue of the mouth (inner cheeks, tongue, and/or gums). It can be caused by an infection, irritation, trauma to the mouth, and allergies. Stomatitis can be painful and may lead to canker sores and cold sores, which may make it hard for you to talk or eat.

Aphthous stomatitis is a common condition in which canker sores caused by stomatitis come back on a fairly regular basis.

This article will go over what stomatitis is, why it occurs, and how it can be treated.

A man pulling down his bottom lip
Mohd Akhir / EyeEm / Getty Images

Stomatitis Symptoms

The severity of symptoms in stomatitis varies widely and may be related to the underlying cause of stomatitis. For some people, stomatitis may just be annoying or mildly bothersome. For others, it may be quite painful and make it difficult to eat and drink normally. Here are some common symptoms of stomatitis:

  • Pain or irritation on the lips, cheeks, gums, tongue, or sides of the mouth
  • You may have a "burning sensation" in the mouth
  • Ulcers, sores, or blisters inside the mouth or on the lips
  • Red patches in the mouth

Stomatitis Causes

There are many potential causes of stomatitis including:

  • Injury from surgery
  • Orthotics (such as braces or dentures)
  • Biting the tongue or cheek
  • Burns from hot food or drinks
  • Thrush
  • Chronic dry mouth
  • Tobacco use
  • Sexually transmitted diseases
  • Herpes viruses
  • Side effects of chemotherapy, radiation, or other medications
  • Chemical exposure
  • Certain allergies
  • Stress or a weakened immune system
  • Bacteria infections
  • Nutritional deficiencies
  • Bechet's disease
  • Crohn's disease
  • Lupus


Many cases of stomatitis, especially canker sores or cold sores, can be diagnosed through a physical exam and a medical history including a history of your symptoms and any medications you are taking.

In other cases, blood work or allergy testing may be necessary. In more complicated cases your healthcare provider may take a biopsy or a skin scraping of the lesion for testing to determine exactly what is causing your stomatitis.

Because it involves the mouth, stomatitis is sometimes first diagnosed by a dentist rather than a medical healthcare provider. Although, your dentist may send you to your regular healthcare provider for follow up.

Stomatitis Treatment

Some cases of stomatitis—such as a mild case of canker sores—require no treatment. If treatment is required for stomatitis, it will depend on the underlying cause. For example, underlying allergies or infections may need to be identified and treated accordingly.

Although each case will be different, your healthcare provider may recommend some of the following treatments to ease the pain of stomatitis or to aid in the healing process:

  • Over-the-counter (OTC) pain relievers such as acetaminophen or ibuprofen
  • Topical medications that help with pain or inflammation
  • Drinking more fluids to keep the mucous membranes well hydrated
  • Mouthwashes such as salt water (alcohol-based mouthwash should be avoided)
  • Antiviral creams for cold stores are available over-the-counter, they should be applied as soon as you notice the cold sore coming on
  • If you have injured the inside of your mouth from braces or dentures there are wax-based products that can be applied to protect the area
  • Over-the-counter produce called Kanka creates a barrier layer over mouth lesions that can aid in pain relief
  • Avoiding food that is very spicy, acidic, or very hot in temperature as these may further inflame the mucous membranes

More About Canker Sores

The exact cause of canker sores is unknown but the condition is extremely common. Canker sores most often have a red base with a yellow top, but this is not always their appearance. The lesions can range in severity from an annoyance to extreme pain and typically last one to two weeks before they heal. They also vary in size, but the majority of canker sores are quite small and do not leave scars.

One suspected cause of canker sores is that they are brought on when you are stressed out or your immune system is not functioning well. Canker sores could also be caused by certain medications, nutritional deficiency, or by eating certain foods including:

  • Potatoes
  • Coffee
  • Chocolate
  • Cheese
  • Citrus fruits
  • Nuts

Recurring canker sores (aphthous stomatitis) are most common in kids and teenagers between the ages of 10 to 19 years. While they can be painful, canker sores are not usually harmful to your overall health prognosis.

More About Cold Sores

Cold sores are caused by the herpes simplex virus (HSV) and are sometimes called fever blisters. The painful sores can appear on the lips, chin, cheeks, inside the nostrils or inside the mouth. They are extremely common.

More than half the population in the United States has cold sores from a herpes infection.

Cold sores last on average seven to 10 days before they heal, usually without treatment, and are extremely contagious. Once an individual has been infected with HSV they remain infected for life and cold sores will come and go. These individuals are especially likely to develop cold sores when their immune system is not functioning well.

When cold sores first appear they can feel itchy or tingly. This usually progresses to a fluid-filled sore which will eventually burst and ooze. After that, a yellow crust will form on top of the sore which will then scab and heal. People who get cold sores often get them in the exact same place repeatedly. The lower lip is the most common place to get them.

You should avoid kissing anyone while you have a cold sore, sharing chapstick or drinks, or touching the cold sore to prevent the spread of the infection. If you touch your cold sore by accident, wash your hands with soap and water immediately.

When to See a Healthcare Provider for Stomatitis

You should see a healthcare provider if you have unexplained symptoms of stomatitis or symptoms that last longer than a week or two. You should also seek medical attention if you are having trouble eating and drinking and could be in danger of dehydration.

Other reasons to see a healthcare provider may include white patches on the tongue or sores in the mouth accompanied by a high fever. Do not hesitate to contact a healthcare provider for worrisome symptoms.

Frequently Asked Questions

  • What is the best treatment for stomatitis?

    Stomatitis is treated by addressing its underlying cause. For example, if stomatitis is caused by tobacco use, then a person will be advised to stop smoking tobacco. Or, if an allergy is the cause, then finding effective allergy treatment can help treat and prevent stomatitis.

  • Is there medicine for stomatitis pain?

    Yes, there are medicines to treat pain caused by stomatitis. For example, your healthcare provider may recommend over-the-counter pain relievers, a saline solution, or an antiviral cream.

  • Is stomatitis bacterial or viral?

    A viral or bacterial infection can cause stomatitis.

  • How do I get rid of canker sores?

    Simple canker sores will usually heal on their own within one to two weeks. If a sore becomes painful, you can use an over-the-counter oral care product that numbs the affected area to reduce pain. Also, home remedies like a saltwater solution can speed up healing.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Edgar NR, Saleh D, Miller RA. Recurrent Aphthous Stomatitis: A Review. J Clin Aesthet Dermatol. 2017;10(3):26-36.

  2. Plewa MC, Chatterjee K. Aphthous Stomatitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-.

  3. B. Hennessy. Stomatitis (Oral Mucositis). Merck Manual Professional Version.

  4. Lankarani KB, Sivandzadeh GR, Hassanpour S. Oral manifestation in inflammatory bowel disease: a review. World J Gastroenterol. 2013;19(46):8571-9. doi:10.3748/wjg.v19.i46.8571

  5. Bertsias G, Cervera R, Boumpas DT. Systemic lupus erythematosus: pathogenesis and clinical features. EULAR textbook on rheumatic diseases. Geneva, Switzerland: European League Against Rheumatism, 2012. pp. 476–505.

  6. American Academy of Family Physicians. Canker Sores.

  7. Cincinnati Children's Hospital Medical Center. Aphthous Stomatitis (Canker Sores).

  8. Chi CC, Wang SH, Delamere FM, Wojnarowska F, Peters MC, Kanjirath PP. Interventions for prevention of herpes simplex labialis (cold sores on the lips). Cochrane Database Syst Rev. 2015;(8):CD010095. doi:10.1002/14651858.CD010095.pub2

By Kristin Hayes, RN
Kristin Hayes, RN, is a registered nurse specializing in ear, nose, and throat disorders for both adults and children.