Leukoplakia is a condition that develops when cells within the mucous membrane change. This often occurs in response to chronic irritation and causes white lesions within the mouth. These may develop on the inner cheeks, lips, gums, tongue and roof or floor of the mouth.

Many different factors can irritate the lining of the mouth. The primary cause is tobacco use, and includes tobacco products that are smoked, chewed or held in the mouth. Alcohol consumption is another common cause of the irritation that can lead to leukoplakia. When combined, tobacco and alcohol consumption can significantly raise the risk for a person developing leukoplakia. Vitamin deficiency, syphilis and endocrine disturbances can also cause leukoplakia.

In a small number of cases (about 3 percent), leukoplakia may lead to oral cancer. Patients should consult their dentist if they have a mouth sore or area of discoloration that lasts a week or longer. If red lesions (erythroplakia) occur in or near the leukoplakia, it may indicate the development of cancer.

A different type of leukoplakia, called hairy leukoplakia, is also characterized by white lesions inside the mouth. However, these areas appear fuzzy and ridged. Hairy leukoplakia most often occurs on the tongue and is due to a viral infection (Epstein-Barr virus). This virus becomes activated by an immune system deficiency. It is most common in people infected with human immunodeficiency virus (HIV) who have been previously exposed to the Epstein-Barr virus. Unlike leukoplakia, hairy leukoplakia does not increase the risk of oral cancer.

A dentist can usually diagnose leukoplakia based on its appearance and location within the mouth. An examination of the entire mouth is usually performed, including inspection of all sides of the tongue. A dental history and medical history may be obtained, and patients may be asked whether they have a family history of leukoplakia or oral cancer. An oral brush biopsy, a quick and painless procedure, may be performed as a screening test to determine whether signs of cancer exist within the lesion. This may be followed with a scalpel biopsy, which may confirm a diagnosis of cancer.

Treatment for leukoplakia generally involves removing all irritating factors causing the condition. Eliminating tobacco use and avoiding or limiting alcohol consumption is important. It may also involve correcting any ill-fitting dental appliances or smoothing rough tooth surfaces in the mouth. Leukoplakia typically goes away within a year after the cause is removed. Prevention involves continuing these activities. Regular dental examinations and a diet high in fruits and vegetables (especially those that contain beta carotene) may also help.