Lichen planus

Many people get lichen (LY-kin) planus (PLAN-us). This disease can develop on one or several parts of the body. It can appear on the skin or inside the mouth. Sometimes, it appears in both places. Lichen planus can even change the way a person’s fingernails or toenails look. It also can appear on the genitals or a person’s scalp.

Lichen planus is not contagious. You cannot get this disease from someone else, and you cannot give it to anyone.

Lichen planus is not a type of cancer.

Source: https://www.aad.org

Signs, symptoms

The signs and symptoms of lichen planus depend on where it appears on the body.

Skin

On the skin, lichen planus often causes bumps that are shiny, firm, and reddish purple. Sometimes the bumps have tiny white lines running through them. These lines are called Wickham’s striae.

Most people get a few bumps. Some people get many bumps, which can appear on different parts of the body. The most common places for these bumps to appear are the wrists, lower back, and ankles, but they can appear anywhere on the skin, including the genitals.

On the legs, the bumps tend to be darker.

New bumps may appear as older bumps clear.

When lichen planus develops on the skin, a person can have the following:

• Thick patches of rough, scaly skin. If bumps continue to appear in the same place, thick patches of rough, scaly skin can form. These patches develop with time and are most common on the shins and around the ankles.
• Itch. Sometimes the bumps and patches itch. The thick patches are most likely to itch.
• Blisters. These are rare.
• Pain, especially on the genitals. The skin can be bright red and raw. Open sores can appear. These can make sex painful or impossible.

Mouth (oral lichen planus)

When lichen planus appears inside the mouth, it most commonly occurs on the insides of the cheeks. It also can appear on the tongue, lips, and gums. Inside your mouth, you may have:

• Patches of tiny white dots and lines that can look like lace.
• Redness and swelling.
• Peeling on the gums.
• Painful sores (can hurt or burn).

Nails

When lichen planus appears on the nails, it often appears on just a few nails. Sometimes it appears on all of the nails on a hand or foot. You may see:

• Ridges or grooves on the nails.
• Splitting or thinning.
• Loss of nails (can be temporary or permanent).

Scalp (lichen planopilaris)

It is rare, but this disease can develop on the scalp. If it does, you may have the following on your scalp:

• Redness and irritation.
• Tiny bumps.
• Thinning hair or patches of hair loss.
• Scars (appear slowly).

Source: https://www.aad.org

Who gets, causes

Who gets lichen planus?

Anyone can get lichen planus. It is most common in middle-aged adults. Women get lichen planus in their mouths more often than men do.

What causes lichen planus?

What causes most cases of lichen planus remains unclear. One theory is that lichen planus is an autoimmune disease. This means the person’s immune system reacts as though the skin and other parts of the body are foreign. When this happens, the body starts to attack itself. To find out whether lichen planus is an autoimmune disease, we need more research.

We do know the following:

• Some medicines can cause a rash that looks like lichen planus. These medicines include diuretics (treatment for high blood pressure and heart disease) and medicine taken to prevent malaria. Be sure to tell your dermatologist about every medicine that you take.
• In the mouth, a metal filling may be the cause. This is rare, but it can happen. If this is the cause, replacing the metal filling with a non-metal filling will get rid of the lichen planus.
• A rare type of lichen planus, familial bullous lichen planus, runs in families. Other forms of lichen planus do not seem to run in families.
• There may be a link between lichen planus and infection with the hepatitis C virus. Many people with hepatitis C also have lichen planus. Your dermatologist may check to see whether you have this virus.

Source: https://www.aad.org