Dear Dr Jeff: What exactly are canker sores? How do you treat them?-B.L.
Dear B.L.: Canker sores are benign, open sores that appear on the inner mucous membranes of the mouth. They may occur at any age, but usually begin in adolescence. They apparently occur more often in women than in men. Although their cause is unknown, many researchers have attempted to identify an infectious agent and some suspect a still unidentified member of the Herpes virus family. They seem to be triggered by other illnesses, stress, dietary deficiencies (especially iron, folic acid or vitamin B12), food allergies, and hormonal changes (especially menstrual).
Canker sores usually begin with a tingling or burning sensation, followed by painful, red spots, or bumps which ulcerate, forming open sores, often in clusters. Their centers appear white or yellow, and they are often surrounded by raised, reddened edges. After four to seven days or so, they become covered with gray-colored membranes and are less painful. Complete healing may take an additional one to two weeks. Recurrence is frequent and almost universal.
Uncommonly, canker sores are accompanied by more generalized systemic symptoms as fever, malaise, fatigue, and swollen lymph nodes. In this setting, canker sores are clinically indistinguishable from the lesions of Herpetic stomatitis, an illness of infants and young children clearly caused by the Herpes Simplex Virus. Unlike Herpes, however, canker sores do not respond to antiviral medications and do not seem to be contagious.
Prolonged or severe mouth ulcers may be a sign of other problems as well, such as allergic drug reactions and dermatologic diseases or cancers. Mouth ulcers can be very extensive and slow-healing in people who are receiving chemotherapy or other immunosuppressive medications or who have HIV.
The vast majority of canker sores are pretty clearly garden-variety ones that require no special evaluation or treatment. Although no curative therapies have been found, people have tried a number of home remedies to reduce symptom severity.
A variety of mouthwashes seem to help. Try gargling with warm salt water, three or four baby aspirin dissolved in warm water, or my favorite, liquid Benadryl mixed with an equal amount of a white antacid like Mylanta. Rarely, and really only for very extensive and slow healing sores, oral tetracycline or steroid washes can be prescribed. The herbal remedy Goldenseal has also proved helpful, either used in suspension as a mouthwash, or applied to the sores as a paste.
No proven preventive measures for canker sores have been found. Good oral hygiene, overall good health, rest, and nutrition no doubt help. Stress reduction probably helps too!
Fortunately, B.L., though a pain in the mouth, canker sores are relatively short-lived and almost always resolve themselves naturally.
Jeff Benson, M.D.
Dudley Coe Health Center