Mouth sores can be annoying, painful and unsightly. They can be caused by bacterial, viral or fungal infections, a loose orthodontic wire, a denture that doesn’t fit, or a sharp edge from a broken tooth or filling. Among the most common mouth sores are canker sores and cold sores.
Canker sores are small ulcers with a white or gray base and a red border. Unlike cold sores, canker sores appear inside the mouth. Their exact cause is uncertain but 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 two. Over-the-counter topical anesthetics and antimicrobial mouthrinses may provide temporary relief. Stay away from hot, spicy or acidic foods that can irritate the sore. Antibiotics and some oral bandages can reduce secondary infection.
Cold sores are also called fever blisters or herpes simplex. They are groups of painful, fluid-filled blisters that often erupt around the lips and sometimes under the nose or around the chin.
Cold sores caused by herpes virus type 1 are very contagious. The initial infection (primary herpes), which often occurs before adulthood, may be confused with a cold or flu and can cause painful lesions to erupt throughout the mouth.
Once a person is infected with primary herpes, the virus stays in the body and causes occasional attacks. For some people, the virus remains inactive. However, an attack 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 these kinds of viral infections.© American Dental Association. All rights reserved. Reproduction or republication is strictly prohibited without the prior written permission from the American Dental Association.