Lichen Planus

Lichen planus (like-en play-nes) is a skin condition that causes a rash to develop on one area of your body or several parts of your body at the same time. It can affect your:

• Skin.
• Inside of your mouth (oral mucosa).
• Scalp (skin on your head usually covered with hair).
• Nails.
• Genitals (penis, vagina and vulva).

Lichen planus is a lichenoid dermatoses. Healthcare providers use the term used to characterize skin disorders according to the presence of firm, raised, discolored bumps on your skin.

Is lichen planus an autoimmune condition?

Lichen planus isn’t an autoimmune condition, but it can cause a similar response. It’s an idiopathic (meaning the cause is unknown) condition that causes inflammation in your skin. In lichen planus, your body’s immune system attacks parts of your body instead of protecting your body from foreign invaders like bacteria or viruses.

In a healthy immune system, special cells in it called T cells help protect your body from infection. In people with lichen planus, their immune system’s T cells attack a protein in their skin and mucus membranes.

No one knows why the T cells attack the protein.

What is the difference between lichen planus and lichen sclerosus?

Lichen planus and lichen sclerosus are both idiopathic conditions that affect your skin, especially mucus membranes.

Lichen sclerosus is a long-term skin condition that causes your skin to gradually become thinner, itch, develop sores and eventually scar. It can occur anywhere on your skin, but it mainly affects the skin around your genitals and anus (anogenital region). It occurs more commonly in people who have gone through menopause.

The difference between lichen planus and lichen sclerosus is that lichen sclerosus rarely affects the mucous membranes in your mouth.

What’s the difference between lichen planus and psoriasis?

Lichen planus and psoriasis are both skin conditions that can cause discolored rashes. The main difference between lichen planus and psoriasis is that psoriasis is scaly and typically won’t affect the inside of your mouth.

Who does lichen planus affect?

Anyone can get lichen planus. However, you’re more likely to develop it if you’re between 30 and 60 years old and assigned female at birth.

Some studies suggest people with uteruses might get lichen planus twice as often as people assigned male at birth, and they’re more likely to develop it in their 60s. Males are more likely to develop it in their 40s.

If you have lichen planus on your skin, you’re 50% to 75% more likely to have it in your mouth.

How common is lichen planus?

Lichen planus affects approximately 0.22% to 1% of the adult population. Oral lichen planus affects 1% to 4% of the world population.

How does lichen planus affect my body?

Lichen planus commonly affects the skin around your wrists and elbows (flexor surfaces), the back of your hands (dorsal surfaces) and the fronts of your lower legs.

About half of all people who have lichen planus develop oral lichen planus, which affects the skin inside of your mouth and your tongue.

The affected spots (lesions) on your body usually start as tiny, raised dots (papules) that are about the size of the tip of a pin (0.4 millimeters [mm]). They may grow up to the width of a pencil (1 centimeter [cm]).

Oral lichen planus typically starts as tiny white dots on the skin inside of your cheeks or your tongue. In severe cases, the surrounding skin may become inflamed, and sores may develop.