What Is Stomatitis?

It's very likely that you have suffered from stomatitis, a painful and annoying condition. Find out what it is, its causes, and its treatment below.
What Is Stomatitis?
Sandra Golfetto Miskiewicz

Written and verified by la médico Sandra Golfetto Miskiewicz.

Last update: 03 February, 2023

Stomatitis is a condition that can be caused by a wide variety of diseases and refers to an inflammation of the mouth. It can affect the cheeks, gums, lips, tongue, and the base of the mouth. It may occur as simple redness and edema (swelling) in the oral cavity or with canker sores (a single one or many) that are usually painful.

Among oral lesions, canker sores are one of the most frequent causes of medical consultation. Although most of the time they’re benign lesions that are self-limited, a differential diagnosis is necessary in order to establish the most appropriate treatment.

When we speak of oral thrush, we’re referring to lesions with an ulcerous appearance, a white background, and reddened edges that are painful most of the time.

In some people, such as the elderly or cancer patients, stomatitis should be given special attention because it can make it difficult to eat and lead to dehydration and malnutrition. It can also cause problems as a result of inadequate or incomplete oral hygiene.

We’ve already mentioned that stomatitis could be due to undiagnosed diseases. Let’s have a look at them.

Causes of stomatitis

There are many causes of stomatitis. It can be caused by a local infection, a systemic disease, physical or chemical irritants, allergic reactions, and in many other cases the etiology is unknown. The most common specific causes are the following :

  • Recurrent aphthous stomatitis
  • Viral infections, particularly herpes simplex and shingles
  • Other infectious causes such as those produced by fungi and bacteria
  • Trauma
  • Irritants: cigarettes, food or chemicals
  • Chemotherapy and radiotherapy
  • Systemic diseases

We’ll now analyze each of these causes in more detail.

Recurrent aphthous stomatitis

  • This is a chronic inflammatory disease of the oral mucosa that occurs with the recurrent appearance of thrush.
  • It’s very common, and, according to the MSD Manual, it affects 20-60% of adults and a large percentage of children.
  • The specific cause isn’t known.
  • There’s no curative treatment. The therapy is based on reducing symptoms such as pain.

Viral infections

  • This is the most common cause of infectious stomatitis.
  • It can be caused by the herpes simplex virus or the varicella-zoster virus. These two types of virus are characterized by remaining dormant in the nerves and sprouting in times of stress or immunosuppression.

Bacterial and fungal infections

  • Bacterial infections can come from microorganisms that are normally present in the mouth or be introduced from the outside, such as the bacteria that cause syphilis and gonorrhea (both are sexually transmitted infections).
  • During the first phase of a syphilis infection, a sore may appear in the mouth – these aren’t painful. After several weeks, if it isn’t treated, it turns into a whitish plaque. Don’t be fooled by the fact that it doesn’t hurt, as both the ulcer and the whitish plaque can transmit the disease. You need to see your doctor for treatment.
  • Candida albicans is a fungus that is normally present in the mouth, but in immunosuppressed people (cancer patients, HIV patients or those taking steroids) it can spread uncontrollably. The disease appears as whitish, cheese-like plaques, and underneath these plaques the skin is red.


  • Any type of injury to the oral mucosa, such as accidentally biting the cheek or injuring yourself with a sharp tooth or braces, can cause a mouth ulcer.

Irritant substances

Stomatitis is common in people who smoke.
People who smoke a lot are at higher risk of developing stomatitis.
  • Some foods or chemical substances (toothpaste, rinses, among others) can trigger an allergic reaction causing pain in the mouth.
  • The chemicals in cigarettes can be irritating. In addition, they can cause dry mouth, increased temperature, changes in acidity, and decreased resistance to viruses, bacteria and fungi.

Drugs or medications

  • Some types of chemotherapy and radiation therapy used in cancer patients can cause stomatitis.
  • On rare occasions, some antibiotics cause stomatitis.

Systemic diseases

  • Behcet’s disease: This is a condition that causes inflammation in various organs apart from the mouth, such as the eyes, skin, joints, blood vessels, brain, and gastrointestinal tract.
  • Stevens-Johnson syndrome: This is a severe allergic reaction characterized by multiple skin lesions, including blisters.
  • Inflammatory bowel disease: Specifically, Crohn’s disease, which in addition to affecting the gastrointestinal tract, can cause lesions in the mouth.
  • Celiac disease: Caused by gluten intolerance.
  • Lichen planus: This is a skin disease, but it rarely causes oral lesions.
  • Pemphigus vulgaris and bullous pemphigoid: This mainly causes blisters on the skin.
  • Malnutrition: A deficiency of iron and vitamins such as B and C.

When should I be concerned?

Most of the time stomatitis is benign, and usually takes 1 to 2 weeks to fully resolve. However, there are a few red flags to be aware of:

  • Having blisters on the skin
  • Having a fever
  • Eye inflammation
  • Being a person with a known immunodeficiency.

If you have warning signs, it’s important to see your doctor immediately. If the stomatitis lasts more than 2 weeks, is recurrent, bloody, or very painful, then you should see a doctor promptly.

How is stomatitis evaluated?

The doctor will ask you several questions to try to find out the cause of this stomatitis.

  • They will ask you questions about your current illness – how long have you had stomatitis, what triggered it (foods, drugs, mouthwash, etc.), severity of pain, and other associated symptoms.
  • Medical conditions you have/have had.

After doing this, they will examine you physically. First, a general evaluation is carried out to determine if you have fever or other symptoms that would indicate a systemic illness. The mouth is inspected for the type, location, and number of lesions.

Depending on their suspicions, the doctor will also evaluate other mucous membranes such as those in the area of the genitals in search of lesions. If there are blisters on the skin, the doctor will gently rub over the lesion or adjacent skin. This maneuver is used to show the Nikolsky sign, which if positive, the upper layers of the epidermis will move or detach. This is typical of pemphigus vulgaris.

Complementary studies

If you have acute symptoms and there appear to be no systemic symptoms, there will probably be no need for further study.

If not, your doctor may order blood tests, including hematology, iron values, vitamin B12, folic acid, and antibodies to rule out celiac disease.

Culture samples of the lesion may also be performed to identify the underlying organism, as well as biopsies to rule out a neoplastic (cancerous) lesion.

Is there any treatment?

Stomatitis can be treated with general measures.
Proper oral and dental hygiene is important in order to prevent and control stomatitis.

As explained above, if stomatitis doesn’t show any alarming signs, it can be treated at home with simple measures. Although in the case of recurrent benign stomatitis or stomatitis caused by viruses, the germ is not eradicated, the treatment will still reduce pain and the patient will be able to eat better and the healing process will be quicker.

Among the general measures, the following is recommended:

  • The use of soft toothbrushes.
  • Avoiding drinking very hot drinks – cold drinks can help relieve symptoms.
  • Eating softer foods to avoid rubbing the affected area.
  • Avoiding spicy or acidic foods.

The topical treatment is applied directly to the injured area. It’s based on the use of the following:

  • Anesthetics
  • Protective covers
  • Corticosteroids
  • Saline solution

You can find rinses with anesthetics (lidocaine type) in the pharmacy, with which you rinse your mouth for 2 minutes every three hours as needed. Once done, the solution is spat out and shouldn’t be rinsed with water. Lidocaine in its gel form can be spread directly on the lesion.

Swallowing antacids containing sucralfate or aluminum-magnesium serve as a protective cover to relieve pain. If the doctor is sure it isn’t an infection, they may prescribe a corticosteroid rinse or gel to decrease inflammation.

Some pharmacies prepare a so-called “magic mouthwash”, which generally doesn’t have a standard formula, but does contain at least three of the following ingredients:

  • Antihistamine or Anticholinergic: Helps relieve pain.
  • Local anesthetic: Relieves pain.
  • Antacid
  • Corticosteroids: reduce inflammation.
  • Antifungal: reduces fungal growth.
  • Antibiotics: eliminate the bacteria present.

Last, but not least, as an alternative to the previous treatments, rinsing with a saline solution may be recommended. If the doctor doesn’t suspect a benign lesion, or a more severe pathology has been confirmed, a specific treatment for that condition will be applied.

What information should we remember?

Stomatitis is a symptom, not a diagnosis, therefore it’s necessary to investigate the cause. Most of the time, stomatitis is a benign pathology that is treated with topical remedies that relieve pain and thus accelerate the healing process.

It’s important to see your doctor if you have symptoms or warning signs, in order for them to evaluate you and prescribe you the necessary treatment.

Este texto se ofrece únicamente con propósitos informativos y no reemplaza la consulta con un profesional. Ante dudas, consulta a tu especialista.