Canker sores are a type of shallow mouth ulcer that occurs in the inside of the mouth on the inside of the lips, the inside of the cheeks, the gums, the tongue or the roof of the mouth. Another name for canker sores is “aphthous ulcers.” Canker sores can be extremely painful, especially when trying to eat or drink something, especially acidic foods or beverages. Canker sores have a yellow or white core surrounded by a red, inflamed area. Most cases of canker sores are minor canker sores; these sores are relatively small and occur singly. Larger, deeper sores are called major canker sores; this type of canker sore takes longer to heal. If canker sores occur in clusters of much smaller sores, they are called herpetiform canker sores.
Canker sores and cold sores (fever blisters) should not be confused. Canker sores are not contagious to other people or to other parts of the body, and they do not appear on the outside of the lips. Cold sores are blisters (not ulcers) caused by the herpes simplex virus, and they are extremely contagious. It is rare for cold sores to appear on the inside of the mouth, although it does sometimes occur.
Canker sores can have a number of causes. One of the most common causes is minor trauma to the lining of the inside of the mouth followed by an immune response. Hormonal changes during menstrual periods, vitamin deficiencies, food sensitivities, Helicobacter pylori infection and stress can also cause mouth ulcers. Certain medical conditions, such as Crohn’s disease, celiac disease, ulcerative colitis, Behcet’s disease and HIV/AIDS, are also associated with increased numbers of canker sores.
The pain from most canker sores will diminish within a period of a few days, even though the sore is still visible. It usually takes approximately two weeks for a canker sore to heal completely. Rinsing the mouth out with a saline (salt and water) solution may help with canker sores. Medical treatment is usually not required for canker sores, but severe cases may benefit from medications. Medications that are available include mouthwashes and topical creams to reduce the pain of canker sores. In the most severe cases, oral corticosteroids or drugs like colchicine may be used to control the immune response; these drugs are the last line of treatment, however. If your canker sores are found to be caused by a vitamin deficiency, nutritional supplements may be prescribed. For any mouth sore that does not heal, be sure to see your doctor.