Mouth Sores and Inflammation

Viruses are the most common infectious causes of mouth sores. Cold sores of the lip and, less commonly, ulcers on the palate caused by the herpes simplex virus are perhaps the most well known. However, many other viruses can cause mouth sores. Varicella-zoster, the virus responsible for chickenpox as well as the painful skin disorder called shingles, can cause multiple sores to form on one side of the mouth. These sores are the result of a flare-up of the virus, which, just like herpes simplex virus, never leaves the body. Occasionally, the mouth remains painful for months or years or even permanently after the sores have healed.

Cold Sore

3D Model

A bacterial infection can lead to sores and swelling in the mouth. Infections may be caused by an overgrowth of organisms normally present in the mouth or by newly introduced organisms, such as the bacteria that cause syphilis or gonorrhea. Bacterial infections from teeth or gums can spread to form a pus-filled pocket of infection (abscess) or cause less localized inflammation (cellulitis).

Syphilis may produce a red, painless sore (chancre) that develops in the mouth or on the lips during the early stage of infection. The sore usually heals after several weeks. About 4 to 10 weeks later, a white area (mucous patch) may form on the lip or inside the mouth if the syphilis has not been treated. Both the chancre and the mucous patch are highly contagious, and kissing may spread the disease during these stages. In late-stage syphilis, a hole (gumma) may appear in the palate or tongue. The disease is not contagious at this stage.

The yeast Candida albicans is a normal resident of the mouth. However, it can overgrow in people who have taken antibiotics or corticosteroids or who have a weak immune system, such as people with AIDS. Candida can cause whitish, cheese-like patches that destroy the top layer of the lining of the mouth (thrush) when wiped off. Sometimes only flat, red areas appear.

Stomatitis Caused by Candida

Image

Photo provided by Jonathan A. Ship, DMD.

Any type of damage or injury to the mouth, for instance, when the inside of the cheek is accidentally bitten or scraped by broken or jagged teeth or poor-fitting dentures, can cause blisters (vesicles or bullae) or ulcers to form in the mouth. Typically, the surface of a blister breaks down quickly (ruptures), forming an ulcer.

Many foods and chemicals can be irritating or trigger a type of allergic reaction, causing mouth sores. Acidic foods, cinnamon flavoring, or astringents may be particularly irritating, as can certain ingredients in common substances such as toothpaste, mouthwash, candy, and gum.

Tobacco use can cause mouth sores. The sores most likely result from exposure to the irritants, toxins, and carcinogens found naturally in tobacco products but may also result from the drying effects on the lining of the mouth, the high temperatures in the mouth, changes to the acidity of the mouth, or decreased resistance to viral, bacterial, and fungal infections.

The most common medications causing mouth sores include certain cancer chemotherapy drugs. Radiation therapy is also a common cause of mouth sores. Medications containing gold, which were once used to treat rheumatoid arthritis and some other autoimmune disorders, can cause mouth sores, but these medications are rarely used because safer and more effective medications are now available. Rarely, people may develop mouth sores after taking antibiotics.

Many diseases affect the mouth along with other parts of the body. Behçet disease, an inflammatory disease affecting many organs, including the eyes, genitals, skin, joints, blood vessels, brain, and gastrointestinal tract, can cause recurring, painful mouth sores. Stevens-Johnson syndrome, a type of allergic reaction, causes skin blisters and mouth sores. Some people with inflammatory bowel disease also develop mouth sores. People with severe celiac disease, which is caused by an intolerance to gluten (a component of wheat and some other grains), often develop mouth sores. Lichen planus, a skin disease, can rarely cause mouth sores, although usually these sores are not as uncomfortable as those on the skin. Pemphigus vulgaris and bullous pemphigoid, both skin diseases, can also cause blisters to form in the mouth.

Nutritional deficiencies of iron, (vitamin B3), vitamin B6, vitamin B12, and vitamin C may also cause mouth sores.

In people with mouth sores, certain symptoms and characteristics are cause for concern for systemic disorders. They include

• Fever

• Blisters on the skin

• Inflammation of the eye

• Any sores in people with a weakened immune system (such as people with HIV infection)

People who have warning signs should see a doctor right away. People who have no warning signs but have a lot of pain, feel generally ill, and/or have trouble eating should see a doctor within several days. All people with a sore that lasts for 10 days or more must be examined by a dentist or doctor to ensure that the sore is not cancerous or precancerous.

Doctors first ask questions about the person's symptoms and medical history. Doctors ask people about their consumption of or exposure to food, medications, and other substances (such as tobacco, chemicals, toothpaste, mouthwashes, metals, fumes, or dust). Doctors need to know about all currently known conditions that might cause mouth sores (such as herpes simplex, Behçet disease, or inflammatory bowel disease), conditions that are risk factors for mouth sores (such as a weakened immune system, cancer, or HIV infection), and the person’s sexual history.

Doctors then do a physical examination. The mouth is inspected, noting the location and nature of any sores. Doctors then do a general examination to look for signs of systemic disorders that could affect the mouth. The skin, eyes, and genitals are examined for any sores, blisters, or rashes.

What doctors find during the history and physical examination often suggests a cause of the mouth sores and the tests that may need to be done.

• Sometimes cultures, blood tests, or biopsy

The need for tests depends on what doctors find during the history and physical examination, particularly whether warning signs are present. People with a brief episode of mouth sores and no symptoms or risk factors for a systemic illness probably require no testing. In people with several episodes of mouth sores, viral and bacterial cultures and various blood tests are done. A biopsy may be done for persistent sores that do not have an obvious cause.

Eliminating foods from the diet one at a time or changing brands of toothpaste, chewing gum, or mouthwash can be useful to determine whether a specific food or mouth care product is causing the sores.

Topical treatments are substances applied directly to an affected part of the body. Topical treatments for mouth sores include

• Anesthetics

• Protective coatings

• Corticosteroids

• Burning with a laser or chemicals

Once doctors are sure that the sore is not caused by an infection, they may prescribe a corticosteroid rinse or a corticosteroid gel to be applied to each sore.