Canker sores are oral ulcers that consist of an open wound inside the mouth. They are often mistaken for cold sores, which appear on the lips. Canker sores are very common, especially in children and adolescents. They are not contagious. The exact cause of canker sores in not known definitively. They are probably a reaction of the immune system, and may also be a consequence of bacterial infections, hormonal disorders, stress, drugs, allergies and iron, folic acid or B12 deficiency.
Canker sores are sometimes linked to disorders and diseases like Crohn disease, celiac, Behcet’s disease or AIDS. There are three common forms of canker sores. Minor sores are small, painful and clear up after three to 14 days. Minor canker sores do not leave scars. Major canker sores are bigger and deeper and they measure more that 1 cm (1/3 inch). They take more time to heal and they leave scars.
The third type are herpetiform sores that look like herpes, or punched-out round lesions. They may cluster together. They take from seven to 10 days to go away. Canker sores tend to come back. Some people have them several times a year.
There are many ways to treat a canker sore. Some of them can be done at home, like trying different rinses. A saline solution works well with cankers sores, as does a mixture of Maalox with Benadryl. Calamine lotion is available over the counter, or in case the pain is severe and interfering with eating or talking, there are products with a numbing ingredient, such as Benzocaine.
There is no definitive cure for canker sores but medical treatment can alleviate the symptoms and reduce the chance of them coming back. Some products based on corticosteriods may be effective if used immediately upon the attack. They are applied locally, usually in the form of a sticking paste.
If there is need for that, a doctor can prescribe lidocaine, which is an anesthetic, to numb the canker sores. If a person has iron, folic acid or Vitamin B12 deficiency, the doctor may prescribe supplements. This therapy, however, is not effective on persons who do not have that deficiency.
Medications like Cimetidine or Carafate have proven to be effective for treating canker sores. However, their use on canker sores has not yet been FDA approved. In extreme cases, doctors may prescribe oral doses of corticosteroids. The side effects include weight gain, a weak immune system, brittle bones, gastric ulcers and others.