The cause is unknown but may be a reaction to certain medications or possibly hepatitis B or C infection.
Typical symptoms include an itchy rash made of red or purple bumps that form into scaly patches appearing on different parts of the body and sometimes in the mouth or on the genitals.
Medications that may be causing lichen planus should be avoided.
Lichen planus usually resolves without treatment, but symptoms may be treated with corticosteroids, exposure to ultraviolet light, or lidocaine-containing mouthwashes.
This disease can last for more than 1 year, and it can recur.
The cause of lichen planus is not known, but it may be a reaction by the immune system to a variety of medications (especially beta-blockers, nonsteroidal anti-inflammatory drugs [NSAIDs], angiotensin-converting enzyme [ACE] inhibitors, sulfonylureas, antimalarials, penicillamine, and thiazides). The disorder itself is not contagious.
Lichen planus of the mouth may occur in some people who have hepatitis B Hepatitis B, Chronic Chronic hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that has lasted more than 6 months. Most people with chronic hepatitis B have no symptoms, but some... read more , have received the hepatitis B vaccine, have hepatitis C Hepatitis C, Chronic Chronic hepatitis C is inflammation of the liver that is caused by the hepatitis C virus and that has lasted more than 6 months. Hepatitis C often causes no symptoms until after it has badly... read more (see table ), or have the liver disorder primary biliary cholangitis Primary Biliary Cholangitis (PBC) Primary biliary cholangitis (PBC) is inflammation with progressive scarring of the bile ducts in the liver. Eventually, the ducts are blocked, the liver becomes scarred, and cirrhosis and liver... read more .
Symptoms of Lichen Planus
The rash of lichen planus almost always itches, sometimes severely.
The bumps usually have angular borders and appear more purple on light skin and more brown on dark skin. When light is directed at the bumps from the side, the bumps display a distinctive sheen. New bumps may form wherever scratching or a mild skin injury occurs.
Sometimes a dark discoloration remains after the rash heals (called hyperpigmentation).
Usually, the rash is evenly distributed on both sides of the body—most commonly on the torso, on the inner surfaces of the wrists, on the legs, and on the genital area. The face is less often affected. On the legs, the rash may become especially large, thick, and scaly. The rash sometimes results in patchy baldness on the scalp.
Lichen planus is not common among children.
About half of people who get lichen planus also develop it in the mouth. Lichen planus in the mouth usually results in lacy, bluish white lines and branches (called Wickham striae). This type of mouth patch often does not hurt, and the person may not know it is there. However, sometimes painful sores form in the mouth, which often interfere with eating and drinking.
In women, lichen planus often affects the vulva and vagina. Up to 50% of women who have lichen planus of the mouth have undiagnosed lichen planus of the vulva. In men, lichen planus commonly affects the genitals, especially the head of the penis.
Lichen planus affects the nails in up to 10% of cases. Some people may have only mild symptoms such as discoloration of the nail beds, thinning of the nails, and formation of nail ridges. Other people may completely lose their nails and have scarring from the cuticle at the base of the nail (the nail fold) to the skin under the nail (the nail bed).
Diagnosis of Lichen Planus
A doctor's evaluation
Doctors typically base the diagnosis of lichen planus on how the rash looks and where it appears on the body. However, because many other disorders can look like lichen planus (such as lupus erythematosus Systemic Lupus Erythematosus (SLE) Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more on the skin and candidiasis Candidiasis Candidiasis is a fungal infection caused by several species of the yeast Candida, especially Candida albicans. The most common type of candidiasis is a superficial infection of... read more or leukoplakia Precancerous changes in the mouth Growths can originate in any type of tissue in and around the mouth, including connective tissues, bone, muscle, and nerve. Growths most commonly form on the Lips Sides of the tongue Floor of... read more in the mouth or vagina), doctors typically do a biopsy (examination of tissue under a microscope).
Once diagnosed, doctors may do other liver tests Liver Blood Tests Liver tests are blood tests that represent a noninvasive way to screen for the presence of liver disease (for example, viral hepatitis in donated blood) and to measure the severity and progress... read more and tests for hepatitis B and C infections.
Treatment of Lichen Planus
Measures to relieve itching
Corticosteroid injections, pills, or lotions
Measures to relieve mouth pain
People who have no symptoms do not need treatment. Medications that may be causing lichen planus should be stopped and avoided.
Lichen planus on the skin
Standard treatments can be used to relieve itching (see treatment of itching Treatment Itching can be very uncomfortable. It is one of the most common reasons people see doctors who specialize in skin disorders (dermatologists). Itching makes people want to scratch. Scratching... read more ).
Corticosteroids may be injected into the bumps, applied to the skin, or taken by mouth, sometimes with other medications, such as acitretin, griseofulvin, dapsone, hydroxychloroquine, azathioprine, apremilast, or cyclosporine.
Phototherapy (exposure to ultraviolet light), sometimes combined with the use of psoralens (drugs that make the skin more sensitive to the effects of ultraviolet light) may also be helpful (see sidebar ). Combining ultraviolet A light with psoralens is called PUVA (psoralen plus ultraviolet A). Use of a small band of ultraviolet B light is called narrowband ultraviolet light B (NBUVB).
Lichen planus in the mouth
For painful mouth sores, a mouthwash containing lidocaine, an anesthetic, may be used before meals to form a pain-killing coating. Lidocaine mouthwashes should not be used more frequently than prescribed.
Tacrolimus ointment may also help mouth sores.
Other treatment options include corticosteroid ointments, injections, or pills.
Dapsone, hydroxychloroquine, or cyclosporine taken by mouth may help painful mouth sores. Cyclosporine mouth rinses may also help.
Prognosis for Lichen Planus
Lichen planus usually clears up by itself after 1 or 2 years, although it sometimes lasts longer, especially when the mouth is involved. Prolonged treatment may be needed during outbreaks of the rash. However, between outbreaks, no treatment is needed.
People with painful mouth sores rarely develop oral cancer, but the rash on the skin does not turn cancerous. Mouth sores usually last for life.
Lichen planus in the vagina or vulva may be chronic and hard to treat, which decreases quality of life and may cause scarring.