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).

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.

People who have no symptoms do not need treatment. Medications that may be causing lichen planus should be stopped and avoided.

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.