What is Lichen Planus? - Causes, Symptoms & Treatment

Instructor: Mary Ellen Ellis
Lichen planus is a skin condition that can look and feel uncomfortable. In this lesson, we will explore lichen planus, including the causes, symptoms, and treatment.

Lichen Planus Defined

Inflammation is a normal and healthy response of your immune system to cuts, scrapes, infections, and other injuries. Sometimes, though, inflammation occurs in the body when it shouldn't. We don't always know why this happens. In fact, in most cases, inflammatory diseases have no certain cause or explanation. Such is the case with lichen planus, an inflammatory condition of the skin. It is fairly common and can be uncomfortable and unsightly. On the bright side, it isn't serious or life-threatening, nor is it contagious.

Lichen planus on the legs
lichen planus

Symptoms of Lichen Planus

The most common symptom of lichen planus is a skin irritation. In the majority of people with the condition, this appears as small, reddish-purple bumps with flat tops. They show up mostly on the inner forearm, the wrists, and the ankles, but they can crop up anywhere on the body. The bumps are usually itchy and can turn into blisters, which may burst and scab over. Some people see white streaks running through the bumps.

Less common symptoms of lichen planus include hair loss and/or irritation of the scalp, as well as loss of fingernails or ridges on the fingernails. Some people with the condition report having a metallic taste in their mouth. In fewer cases, the rash of lichen planus can turn into painful ulcers. This is more common when the condition is on the skin of the genital area.

Nail ridges are sometimes seen with lichen planus.
lichen planus nails

Also more uncommon is a form of lichen planus that occurs in the mouth. This is called oral lichen planus, and it can cause sores inside the mouth that are white or bluish in color. These sores may have the same white lines that are seen with the skin rash. Oral lichen planus can be quite painful, especially if left untreated and the sores turn into larger ulcers.

An example of oral lichen planus with white lines
oral lichen planus

Causes of Lichen Planus

There is no known cause of lichen planus, and there is also no cure. Triggers for the onset of lichen planus have been recognized, as have some risk factors. In some cases, the trigger seems to be an allergic reaction that stimulates the immune system. In other cases, a virus, like hepatitis C, may trigger the onset of the rash. Anyone can be affected by lichen planus, but it is mostly found in middle-aged people. Additionally, women are at higher risk than men of getting the oral form of the condition.

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