Section 8. Mouth and Dental Disorders

Chapter 112. Mouth Sores

Topics: Introduction | Canker Sores | Oral Herpes Simplex | Other Mouth Sores

Other Mouth Sores

Injury or irritation--for instance, when the inside of the cheek is accidentally bitten or scraped or when an irritating substance, such as an aspirin, is held against the gums--can cause blisters (vesicles, bullae) to form in the mouth. Typically, the surface of a blister breaks down quickly (ruptures), forming an ulcer. Noncancerous ulcers are invariably painful until healing is well under way. Red overgrown areas on the roof of the mouth can result from poorly fitting dentures or from dentures left in the mouth during sleep.

A rare condition called necrotizing sialometaplasia may follow injury to the mouth. In this condition, a large, gaping sore up to 1 inch in diameter forms on the roof of the mouth within 1 or 2 days of an injury. Despite its unsettling appearance, necrotizing sialometaplasia is relatively painless and heals without treatment in 2 months. A doctor may distinguish the condition from oral cancer on the basis of the symptoms (cancer would take a long time to reach the same size and by then would be painful) and sometimes by performing a biopsy (removing a tissue sample for examination under a microscope).

Bacterial infection can lead to sores and swelling in the mouth. Infections may be caused by an overgrowth of organisms normally present in the mouth or by newly introduced organisms. Bacterial infections from teeth or gums can spread to form a pus-filled pocket of infection (abscess) or cause widespread inflammation (cellulitis). Bacterial infections that spread from decayed lower teeth to the floor of the mouth can cause a very severe infection called Ludwig's angina. This swelling may force the tongue upward and block the airway. Infections from an upper tooth can spread to the brain.

Syphilis may produce a white, painless sore (chancre) that develops in the mouth or on the lips during the early stage of infection (see Section 17, Chapter 200). The sore usually heals after several weeks. About 1 to 4 months later, a white area (mucous patch) may form on the lip or inside the mouth if the syphilis has not been treated. Both the chancre and the mucous patch are highly contagious, and kissing may spread the disease during these stages. In late-stage syphilis, a hole (gumma) may appear in the palate or tongue; at this stage the disease is not contagious.

Herpes zoster, the virus responsible for chicken pox as well as the painful skin disorder called shingles (see Section 17, Chapter 198), can cause multiple sores to form on one side of the mouth. These sores are the result of a flare-up of the virus, which, just like herpes simplex virus, never leaves the body. Herpes zoster is treated much like severe herpes simplex, but occasionally the mouth may remain painful for some time (weeks or months) after the sores are healed.

Behçet's syndrome, an inflammatory disease affecting many organs, including the eyes, genitals, skin, joints, blood vessels, brain, and digestive tract (see Section 5, Chapter 69), can cause recurring, painful mouth sores. Lichen planus, a skin disease, can cause mouth sores as well, although most of the time these sores are not as uncomfortable as those on the skin (see Section 18, Chapter 203). Pemphigus and bullous pemphigoid, both skin diseases, can also cause blisters to form in the mouth (see Section 18, Chapter 209 and Section 18, Chapter 209).