1 The classic lesion is a small (less than 1 centimeter) oval to round ulcer with a erythematous (red) border. 2 They occur on the mucous membranes inside the mouth.anker Sore Overview. Canker sores, also known as aphthous ulcers, are among the most common causes of painful sores in the mouth.
A canker sore is a shallow sore shaped like a crater (ulcer) on your tongue or on the inside of your lip or cheek. Canker sores have a red border and a white or yellow center. They may be painful and can make it hard to talk and eat. You may have one or more than one canker sore at a time. Canker sores are not contagious. Canker sores may also develop when you: 1  Are stressed or tired. 2  Have your menstrual cycle, if you are a woman. 3  Hurt your mouth, such as biting your lip. 4  Have braces on your teeth. 5  Have food allergies. 6  Eating foods that you are allergic to may cause you to get a canker sore. Causes. The precise cause of canker sores remains unclear, though researchers suspect that a combination of factors contributes to outbreaks, even in the same person. Possible triggers for canker sores include: 1  A minor injury to your mouth from dental work, overzealous brushing, sports mishaps or an accidental cheek bite. Canker sores may also occur because of certain conditions and diseases, such as: 1  Celiac disease, a serious intestinal disorder caused by a sensitivity to gluten, a protein found in most grains. 2  Inflammatory bowel diseases, such as Crohn's disease and ulcerative colitis. Stress or tissue injury is thought to be the cause of simple canker sores. Certain foods -- including citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries) -- can trigger a canker sore or make the problem worse. Some cases of complex canker sores are caused by an underlying health condition, such as an impaired immune system; nutritional problems, such as vitamin B-12, zinc, folic acid, or iron deficiency; or gastrointestinal tract disease, such as celiac disease or Crohn's disease. Certain foods -- including citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries) -- can trigger a canker sore or make the problem worse. Overview. A canker sore (aphthous ulcer) is a mouth ulcer or sore that is open and painful. They are the most common type of mouth ulcer. Some people notice them on the inside of their lip or cheek. They are usually white or yellowish and surrounded by red, inflamed soft tissue. Tips to Prevent Canker Sores. You can prevent the recurrence of canker sores by avoiding foods that may have previously caused the outbreak. These often include spicy, salty, or acidic foods. Also, avoid foods that cause allergy symptoms, such as itchy mouth, swollen tongue, or hives. Canker Sore Overview. Canker sores, also known as aphthous ulcers, are among the most common causes of painful sores in the mouth. 1  The classic lesion is a small (less than 1 centimeter) oval to round ulcer with a erythematous (red) border. 2  They occur on the mucous membranes inside the mouth.  The main symptom of a canker sore is getting a shallow ulcer on your tongue or on the inside of your lip or cheek. The sore may be large or small, and it will have a red border and a white or yellow center. You might have more than one canker sore at a time. Canker sores usually begin with a burning or tingling feeling. Canker sores are not contagious. Canker sores may also develop when you: 1  Are stressed or tired. 2  Have your menstrual cycle, if you are a woman. 3  Hurt your mouth, such as biting your lip. 4  Have braces on your teeth. 5  Have food allergies. 6  Eating foods that you are allergic to may cause you to get a canker sore. A canker sore is a little ulcer in the protective lining of your mouth. Unlike cold sores, which are caused by the herpes virus, canker sores are not the result of viral or bacterial infections and are not contagious. They're auto-immune, which means that your body is basically attacking itself. More from YouBeauty.com: 1 Canker sores are small, painful ulcers on the inside of the mouth, tongue, lips, or throat. 2  Symptoms of canker sores include small, painful, crater-like ulcers. 3  See a doctor if canker sores are accompanied by fever, last more than three weeks, or the affected individual has difficulty swallowing. 
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