Oral hairy leukoplakia (OHL) refers to a white patch – or white patches – that can develop in the mouth. These patches usually occur along the sides of the tongue, although they can sometimes develop on the top and underside of the tongue or along the inside of the cheek. Looking carefully at these patches, they may appear shaggy or may contain a number of tiny folds or ridges.


OHL can look like thrush, another common problem characterized by white patches that can develop in the mouths of HIV-positive people. However, thrush usually comes off when it is lightly scraped with a toothbrush, whereas OHL does not.


OHL is often one of the first opportunistic infections to occur in HIV-positive people. It can occur at any T-cell count. HIV-positive people with more than 500 T-cells have developed OHL, but it is most common among HIV-positive people with fewer than 200 T-cells. It is also important to note that OHL can occur in people with healthy immune systems, including those not infected with HIV.


It is considered to be a benign disease, meaning that it rarely causes serious physical problems and does not progress to more serious complications.

OHL is caused by the Epstein-Barr virus (EBV). Most people in the world are infected with EBV. Only in some people, including those with compromised immune systems, does it cause disease.


More than 25% of HIV-positive people develop OHL at some point during the course of their infection. It is most common among HIV-positive men and smokers.


What are the symptoms of OHL?

White patches that are shaggy or ridged in appearance that develop on the sides of the tongue are the classic symptom of OHL. OHL can also cause white patches on the topside or underside of the tongue or along the inside of the cheek. These patches may not appear to be shaggy and may not contain any noticeable ridges or folds.


OHL does not usually cause any other symptoms. Thus, many people may not know that they have OHL unless they inspect their tongues or the inside of their mouths for white patches. These patches do not usually cause discomfort and generally do not affect the taste of foods or liquids. In some cases, however, OHL can cause mild pain and may cause alterations in taste and heightened sensitivity to food temperatures.


How is it diagnosed?

Very often, a health-care professional can diagnose OHL simply by looking at the white patch. If there is confusion as to whether the white patch is OHL or thrush (candidiasis), a simple scrape test can be performed. Using a tongue depressor or a toothbrush, the patch can be lightly scraped. If it appears to come off with scraping, the white patch is probably thrush and not OHL.


To be sure that the white patch is OHL, a health-care provider can send a sample of the patch to a lab for analysis. The lab will look for the Epstein-Barr virus (EBV) to confirm a diagnosis of OHL.


How is it treated or prevented?

OHL usually does not require treatment or cause serious symptoms. However, treatment is an option for people who are unhappy with the appearance of OHL on their tongues or for those with widespread lesions who are experiencing discomfort or altered taste because of the patches.


Antiviral medications, taken by mouth, are the most common method of treating OHL. These medications are usually taken for one to two weeks or until the OHL patches have disappeared:


Acyclovir (Zovirax®): Acyclovir has been used for many years as a treatment for OHL. It is a very safe oral medication. The dose used to treat OHL is 800 mg taken five times a day for at least a week. Taking lower doses of the drug for a prolonged period of time can help prevent OHL from recurring after it is treated. However, this is usually recommended only for patients who have a history of frequent recurrences.


Valacyclovir (Valtrex®): Valacyclovir is a "pro-drug" of acyclovir. Unlike acyclovir, valacyclovir needs to be broken down by the body before its active ingredient – acyclovir – can begin controlling the disease. This allows for higher amounts of acyclovir to remain in the body, thus requiring a lower dose of the drug to be taken by mouth. For the treatment of OHL, valacyclovir only needs to be taken three times a day. Like acyclovir, valacyclovir rarely causes side effects.


Famciclovir (Famvir®): Famciclovir is actually the pill form of a topical cream called penciclovir (Denavir®). Like valacyclovir, famciclovir needs to be taken three times a day until the patches have disappeared.


Other options include tretinoin (Retin A®) and podophyllin resin, two medications that can be applied directly to the OHL patches. Tretinoin is usually applied two or three times a day until the patches have disappeared; podophyllin is applied once or twice over a two- to three-week period by a healthcare provider. Another option, especially if the OHL patches are small, is for a healthcare provider to apply liquid nitrogen (cryotherapy) to the affected area or to remove the patches surgically.


There is no sure way to prevent OHL patches from occurring. However, keeping the immune system healthy is the best possible way to prevent OHL. This means keeping viral load low and T-cells high using anti-HIV drug treatment and by adopting a healthy lifestyle.


Are there any experimental treatments?

At the present time, there are no new medications being developed for the treatment of OHL, given that OHL is not a serious opportunistic infection and medications are available to treat it. However, if you would like to find out if clinical trials of new OHL treatments are being conducted, visit ClinicalTrials.gov, a site run by the U.S. National Institutes of Health. The site has information about all HIV-related clinical studies in the United States. For more info, you can call their toll-free number at 1-800-HIV-0440 (1-800-448-0440) or email contactus@aidsinfo.nih.gov.

Last Revised: January 18, 2016