MOUTH & TEETH Mouth & Gum • Bad breath • Canker sore • Gingivitis • Periodontitis • Oral thrush • Trench mouth • Leukoplakia • Burning mouth syndrome • Oral lichen planus • Geographic tongue

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Leukoplakia is a condition in which thickened, white patches form on your gums, on the inside of your cheeks and sometimes on your tongue. These patches can't easily be scraped off.

The cause of leukoplakia is unknown, but it's considered to result from chronic irritation. Tobacco, either smoked or chewed, is the main culprit, but irritation can also come from other sources, such as long-term alcohol use.

Leukoplakia is the most common of all chronic mouth lesions. Although anyone can develop leukoplakia, it's most common in older men. People with compromised immune systems sometimes develop an unusual form of the disorder called hairy leukoplakia.

In general, leukoplakia isn't painful, but the patches may be sensitive when you touch them or eat spicy foods. Although the disorder usually isn't dangerous, it can be serious. A small percentage of leukoplakic patches show early signs of cancer, and many cancers of the mouth occur next to areas of leukoplakia. For that reason, it's best to see your dentist if you have unusual changes in your mouth lasting longer than a week.

Leukoplakia can have various appearances, but typically first appears as flat, gray or gray-white sores (plaques) — usually on your gums or on the insides of your cheeks and sometimes on your tongue. Over weeks or months, leukoplakia can develop into patches with the following characteristics:

• White color
• Thick, rough or wrinkled texture
• Hardened surface

Sometimes you may also have raised red lesions (erythroplakia), which are more likely to show precancerous changes.

A type of leukoplakia called hairy leukoplakia primarily affects people whose immune systems have been weakened by medications or disease, especially HIV or AIDS. Hairy leukoplakia causes fuzzy, white patches that resemble folds or ridges on the sides of your tongue. It's often mistaken for oral thrush — an infection marked by creamy white patches on the area that extends from the back of your throat to the top of your esophagus (pharynx) and the insides of the cheeks. Oral thrush is also common in people with HIV/AIDS.

The cause of leukoplakia is unknown. Many possible causes have been linked to leukoplakia, including tobacco, long-term alcohol use and other chronic irritants. Though mechanical irritants, such as rough fillings or dentures, were once felt to be a cause of leukoplakia, they're no longer believed to lead to this condition.

Tobacco use appears to be responsible for most cases of leukoplakia. The vast majority of people who develop leukoplakia are smokers, and most leukoplakic patches either improve or disappear within a year after stopping smoking. Chewing tobacco and snuff also play a key role — as many as three out of four regular users of "smokeless tobacco" products eventually develop leukoplakia where they hold the tobacco against their cheeks.

Researchers also have identified both Candida albicans, the fungus that causes oral thrush, and human papillomavirus, the virus that causes genital warts, in leukoplakic patches. But it's not known whether these microorganisms occur as a secondary infection or actually cause leukoplakia.

Oral hairy leukoplakia
Oral hairy leukoplakia results from infection with the Epstein-Barr virus (EBV). Most people are initially exposed to EBV in childhood — often without having any symptoms. But once you've been infected with EBV, the virus remains in your body for life. Normally, the virus is dormant, but if your immune system is weakened, either from disease or certain medications, it can become reactivated, leading to conditions such as hairy leukoplakia.

People living with HIV or AIDS are especially likely to develop hairy leukoplakia. Although the use of antiretroviral drugs has reduced the number of cases, hairy leukoplakia still may affect as many as one-fourth of HIV-positive people, and may be one of the first signs of HIV infection.

Tobacco use puts you at high risk of oral cancer as well as leukoplakia, and drinking alcohol together with smoking further increases your risk. More men than women develop leukoplakia, mainly because men are more likely to both drink alcohol and smoke. On the other hand, women with leukoplakia tend to show more cancerous changes in their mouth tissues than men do.

Sometimes mouth sores can be annoying or painful without being harmful. But in other cases, mouth problems can indicate a more serious condition. For that reason, see your dentist if you have any of the following:

• White plaques or sores inside your mouth that haven't healed within a week
• Lumps or white, red or dark patches in your mouth
• Persistent changes in the tissues of your mouth

Most often, your dentist diagnoses leukoplakia by examining the patches in your mouth and ruling out other possible causes for your symptoms. To help ensure that no early signs of cancer exist, your dentist may remove a tissue sample (biopsy) for analysis. This can involve either removing the entire lesion (excisional biopsy), or a portion of the lesion, removing cells from the leukoplakic patches with a small, spinning brush (oral brush biopsy).

The tissue is then analyzed in a laboratory using a highly specialized imaging system that allows a pathologist to detect a single abnormal cell among hundreds of thousands of healthy cells.

A negative report means no abnormal cells are present. If the report is positive, your dentist is likely to perform another biopsy by removing a small tissue sample and sending it to a laboratory for analysis.

Leukoplakia usually doesn't cause permanent damage to tissues in your mouth and frequently goes away once you remove the irritating factors. Some patches may become inflamed, however, causing ongoing discomfort.

Oral cancer is the most serious complication of leukoplakia. A majority of oral cancers form in the vicinity of leukoplakic patches, and the patches themselves may show cancerous changes. Hairy leukoplakia, on the other hand, isn't painful and isn't likely to lead to cancer. But it may indicate the presence of HIV infection or AIDS.

The usual treatment for leukoplakia is to remove the source of the irritation. For most people, stopping smoking or alcohol consumption clears the condition. When this isn't effective or if the lesions show early signs of cancer, your dentist may choose to remove leukoplakic patches using a scalpel, a laser or an extremely cold probe that freezes and destroys cancer cells (cryoprobe).

Follow-up is necessary after removal because recurrences are frequent. Doctors consider treatment sites remaining disease-free after three years to have healed.

Researchers have investigated the effects of retinoids — derivatives of vitamin A that are used to treat severe acne and other skin conditions — on leukoplakia. Although they appear effective against leukoplakia, retinoids may cause side effects, even when used topically. Beta carotene, an antioxidant that's converted to vitamin A in your body, also may completely or partially reduce leukoplakic patches.

Some research has also shown that vitamin E (alpha-tocopherol) may shrink the lesions associated with leukoplakia. However, more research is needed.

Treating oral hairy leukoplakia
Not all cases of oral hairy leukoplakia need treatment, and your doctor or dentist may take a wait-and-watch approach. If you need treatment, several options are available:

• Systemic medications. These include antiviral drugs such as valacyclovir and famciclovir, which prevent the Epstein-Barr virus from replicating but don't eliminate it from your body. Treatment with antivirals can clear leukoplakic patches within a week or two, but symptoms often return once therapy stops.
• Topical medications. These include podophyllum resin solution and tretinoin (retinoic acid). Podophyllum solution is a mixture obtained from the dried rhizomes and roots of two common plants. When applied topically, it can heal leukoplakic patches, but it may cause some discomfort and affect your sense of taste. In addition, the patches often return several weeks after being treated. Retinoic acid, a vitamin A derivative, seems to inhibit the replication of the Epstein-Barr virus, but as with other treatments, hairy leukoplakia often returns when the treatment ends.

Most often, you can prevent leukoplakia by following these suggestions:

• Stop using tobacco products. Avoiding all tobacco products is one of the best steps you can take for your overall health as well as one of the main ways to prevent leukoplakia. Talk to your doctor about methods that can help you quit. And if friends or family members continue to smoke or use spit tobacco, encourage them to have dental checkups at least two or three times a year. Oral cancers are usually painless until fairly advanced.
• Avoid or limit alcohol consumption. Alcohol is a factor in both leukoplakia and oral cancer. Combining alcohol and smoking greatly increases your risk of both diseases because alcohol makes it easier for the harmful chemicals in tobacco to penetrate the tissues in your mouth.
• Eat plenty of fresh fruits and vegetables. These are rich in antioxidants such as beta carotene, which reduce the risk of leukoplakia by deactivating harmful oxygen molecules before they can damage tissues. Rich food sources of beta carotene include dark yellow, orange and green fruits and vegetables, including carrots, pumpkin, squash, cantaloupe and spinach.