Mouth sores that appear on the lips, roof of the mouth, tongue, gums, or inside the cheeks can be ugly, painful, and annoying. Eating and speaking can be difficult as any movement of the affected tissue can cause discomfort. Two common types of painful mouth sores are canker sores and cold sores.
Canker sores, or apthous ulcers, are usually single small, flat lesions with a white, gray, or yellow center and a red border. Occasionally, they may be large, or there may even be multiple ulcers, but they are almost always painful. There are several different causes of canker sores. Fatigue, stress, or a weakened immune system can trigger the formation of a canker sore. Certain types of foods or even trauma from cheek or lip biting or eating a sharp piece of food can create a canker sore as well. Treatment for canker sores is for relief of discomfort only as there is no cure. Over the counter medications are typically numbing creams or germ-fighting mouthrinses. Occasionally a dentist may prescribe corticosteroids for a patient with multiple reoccurring ulcers. Avoiding spicy and acidic foods and beverages will help minimize the pain of canker sores. Most canker sores heal and disappear within 7-10 days.
Cold sores, or fever blisters, are clusters of fluid-filled blisters that erupt on or around the lips. They can also occur on the gums near the teeth or on the roof of the mouth. After a few days the blisters may break and become a scab. Cold sores are caused by the herpes virus which is contagious. Drinking from the same cup, sharing eating utensils, or kissing someone with a cold sore are some of the ways the virus is transmitted from one person to another. Once a person is infected, the virus can stay in the body in the inactive state for a period of time and may occasionally be activated by irritants like wind, the sun, and stress. Most cold sores heal within a week or two. There is no cure for the virus or the lesion, but topical anesthetics or anti-inflammatory agents available over the counter can provide temporary relief from discomfort. A dentist can prescribe topical antiviral medications, but they must be applied within the first day or two to be of any benefit.
Not all mouth sores are harmless. A lesion that persists for longer than two weeks should be evaluated by a dentist. Based on the appearance, location, and possible causes of the lesion, your dentist will determine whether or not the area needs to be biopsied or evaluated by a specialist.