Canker Sore

Ulcerous sores, also called aphthous ulcers, that develop inside the MOUTH. The typical canker sore is round, with a slightly white center and a red rim. Sometimes a tingling or burning sensation precedes the eruption of the sore. A canker sore is painful and irritating for three to five days, then begins to heal and generally goes away in about three weeks. Researchers do not know what causes canker sores, though the tendency to develop canker sores appears to run in families. Theories about the causes of canker sores include immune function abnormalities, nutritional deficiencies, and FOOD ALLERGIES. Some women notice canker sores are more common when they are menstruating.

Treatment targets relieving the discomfort and may include

• frequently rinsing the mouth with a weak solution of saltwater, hydrogen peroxide, diphenhydramine liquid, or milk of magnesia (rinse and spit, do not swallow any of these solutions)
• applying milk of magnesia or a topical anesthetic preparation for oral use directly to the canker sore with a cotton swab
• taking acetaminophen or a nonsteroidal antiinflammatory DRUG (NSAID) for generalized pain relief
• taking a lysine supplement
• avoiding foods and seasonings that irritate the canker sores

Prescription medications containing amlexanox (such as the brand-name product Aphthasol) may reduce INFLAMMATION and expedite HEALING when sores are large or occur frequently. Such medications come in topical and mouthrinse preparations. Researchers have yet to identify any preventive measures to keep canker sores from developing.