What is Aphthous Stomatitis?

Aphthous stomatitis, also called aphthous ulcers or canker sores, are a very common type of mouth lesion. Most ulcers heal within seven to 10 days, but in some people, recurrent lesions can cause significant pain and damage in the mouth. The cause of aphthous stomatitis is unknown, but the disease has been linked to genetic, nutritional and immunological triggers as well as bacterial infections.

Lesions typically are small, yellowish in color and round or oval in shape. The first sign of lesion development is a burning sensation on the inside of the mouth, with the ulcer itself developing in one to two days. Ulcers are painful to the touch and can make eating and drinking difficult, depending on the location. Pain typically lasts for three to four days, until healing begins. Most small to medium-size lesions heal in two weeks or less. Larger lesions might linger for many weeks or even mouths, with the potential to cause long-lasting damage.

Recurrent aphthous stomatitis can occur in association with risk factors such as mouth trauma, food allergy, gluten sensitivity and chronic infection such as HIV. Recurrent disease can cause repeat episodes of small lesions that measure 0.5 inches (1.25 cm) or less, or larger lesions of more than 0.5 inches. In herpetiform disease, ulcers can recur in groups of a dozen or more ulcers at once, located in clusters inside the mouth.

There is clear evidence that genetics can modify the risk of recurrent canker sores. Many people with this condition have a family history of the recurrent form of the disease. In addition, studies in sets of identical twins have shown that when one twin has aphthous stomatitis sores, the other twin also is likely to develop the disease.

Another correlation that has been noted is that people with recurrent lesions are more likely to be deficient in iron, folic acid and certain B vitamins. Immune system dysfunction also is thought to play a role in pathogenesis, because abnormally high numbers of inflammatory immune cells are found at the site of lesions. Bacterial or viral infection is implicated, but the role of infection in the development of aphthous ulcers is unclear.

Isolated lesions do not require significant treatment, and for most people, topical over-the-counter medications are adequate to treat the pain. Treatment for recurrent aphthous stomatitis might include prescription anti-inflammatory medications, including steroids, and mouthwashes that kill oral bacteria and help reduce inflammation. For people with confirmed nutritional deficiencies, oral vitamins can help reduce the frequency of recurrent lesions. People with gluten sensitivity can avoid foods containing gluten to help reduce the incidence of lesions.