Both annoying and painful, mouth sores can also be a symptom of a disease or disorder. Any mouth sore that lasts a week or longer should be examined. Among the most common are:
Canker sores: Small ulcers with a white or gray base and a red border. Unlike cold sores, canker sores appear inside the mouth. They are not contagious but their exact cause is uncertain. Some experts believe that immune system problems, bacteria or viruses may be involved. Fatigue, stress or allergies can increase the likelihood of a canker sore. A cut caused by biting the cheek or tongue, or reactions from hot foods or beverages may contribute to canker sore development. Intestinal problems, such as ulcerative colitis and Crohn’s disease, also seem to make some people more susceptible. Canker sores usually heal on their own after a week or so. Over-the-counter topical anesthetics, steroid preparations, and antimicrobial mouth rinses can provide temporary relief.
Cold sores: Also called fever blisters or Herpes simplex, these are groups of fluid-filled blisters that occur outside the mouth. Cold sores typically erupt around the lips, under the nose or around the chin. Cold sores caused by herpes virus type 1 are very contagious. Herpes lesions look like multiple tiny fluid-filled blisters that are most common around the edge of the lips. An outbreak may follow a fever, sunburn, skin abrasions or emotional upset. Cold sore blisters usually heal in a week by themselves. Over-the-counter topical anesthetics can provide some relief. Prescription antiviral drugs may reduce the duration of these kinds of viral infections.
Leukoplakia: A thick, whitish-color patch that forms on the inside of cheeks, gums or tongue. These patches are caused by excess cell growth and common with tobacco users. They can result from irritations such as an ill-fitting denture or chewing on the inside of the cheek. A danger is that leukoplakia can progress to cancer. If suspected, painless oral cancer screening will be performed to determine the need for a biopsy.