Lichen Planus

Lichen planus is a skin condition that can cause itchy, flat-topped bumps on your skin and white patches or painful sores inside your mouth. While the exact cause remains unknown, this inflammatory condition affects the skin, mouth, nails, scalp, and genital areas, and often clears up on its own within one to two years.

Table of contents

• What is lichen planus?
• Who gets lichen planus?
• What causes lichen planus?
• Symptoms and clinical features
• How is lichen planus diagnosed?
• Treatment options
• Self-care and lifestyle tips
• What to expect

What is lichen planus?

Lichen planus is a chronic inflammatory condition that affects the skin and mucous membranes. The name refers to a group of skin disorders characterized by firm, raised, discolored bumps on your skin. This condition is not contagious and cannot spread from person to person.^[1][2]

The condition can appear on various parts of your body. It commonly affects the skin on your arms, legs, wrists, lower back, and ankles. Beyond the skin, lichen planus can also affect the inside of your mouth (oral mucosa), your scalp, nails, and genital areas including the penis, vagina, and vulva.^[2]

Although lichen planus is not technically an autoimmune condition, it causes a similar response in your body. In this condition, special cells in your immune system called T cells mistakenly attack proteins in your skin and mucous membranes. No one fully understands why the T cells attack these proteins.^[2][3]

Who gets lichen planus?

Anyone can develop lichen planus, but certain groups of people are more likely to get it. The condition affects approximately 0.22% to 1% of the adult population worldwide, with oral lichen planus affecting 1% to 4% of the world population.^[2][4]

The condition most commonly appears in people between 30 and 60 years of age.^[1][4] Women are affected more often than men, with some studies suggesting that females get lichen planus twice as often as males. Women are more likely to develop the condition in their 60s, while men more commonly develop it in their 40s.^[2]

If you have lichen planus on your skin, you have a 50% to 75% chance of also having it inside your mouth. About half of all people with skin lichen planus develop oral lichen planus.^[2]

What causes lichen planus?

The exact cause of lichen planus is unknown in most cases. However, researchers have identified several factors that may contribute to or trigger the condition.^[3][4]

One significant association is with hepatitis C virus (HCV) infection. Research has found a statistically significant connection between HCV infection and lichen planus. Compared to people without the condition, patients with lichen planus have a greater likelihood of HCV exposure, and patients with HCV infection have an increased likelihood of developing lichen planus. Because of this connection, it is appropriate to screen all patients with lichen planus for hepatitis C.^[6]

Several other factors may contribute to the development of lichen planus:^[4][9]

• Genetic predisposition
• Physical and emotional stress
• Injury to the skin (the condition often appears where the skin has been scratched or after surgery)
• Localized skin diseases such as herpes zoster
• Contact allergies, such as reactions to metal fillings in the mouth
• Certain medications, including drugs used to prevent malaria and to treat high blood pressure, heart conditions, and arthritis

Some research also suggests that vitamin D deficiency may be associated with oral lichen planus, though its relationship with other types of the condition remains unexplored.^[4]

Symptoms and clinical features

Lichen planus can present with a wide range of symptoms depending on which part of the body is affected. Some people may have only a few lesions, while others develop many across different areas.^[1]

Skin lichen planus

When lichen planus affects the skin, it typically creates distinctive lesions that doctors often describe using the “six P’s”: planar (flat-topped), purple, polygonal, pruritic (itchy), papules, and plaques.^[6]

The lesions usually appear as shiny, flat-topped bumps that are firm to touch. They often have a purple or violet color on lighter skin, though they may be harder to see on brown or black skin. The bumps are typically crossed by fine white lines called Wickham striae, which are most easily visible on the inside of the cheeks where oral lichen planus occurs.^[1][3]

The skin lesions commonly appear on the flexor surfaces of the wrists, forearms, lower back, and ankles. They can range in size from pinpoint to larger than a centimeter. The rash may be scattered, clustered, linear (in lines), or arranged in rings.^[4][6]

Itching can range from mild to severe, though some people experience no itching at all. A notable feature is that lesions may appear in a linear pattern following lines of trauma, known as the Koebner phenomenon. As the lesions heal, they often leave behind gray-brown marks (post-inflammatory hyperpigmentation) that can take a year or longer to fade, especially in people with darker skin.^[4][6]

Oral lichen planus

The mouth is often the only affected area, and oral lichen planus commonly involves the inside of the cheeks and the sides of the tongue. The gums and lips may also be involved.^[4]

The most common patterns include painless white streaks or patches that form a lacy pattern. However, some people develop painful sores, burning sensations, or red, swollen tissues. These symptoms can make eating, drinking, and even speaking uncomfortable.^[1][5]

Other affected areas

Lichen planus can affect several other parts of the body:^[1][4]

• Scalp: Can cause bald patches to appear
• Nails: May cause rough, thinning nails with grooves, ridges, or even nail loss
• Genital area: Can create sore red patches on the vulva or ring-shaped purple or white patches on the penis

Different types of lichen planus

The condition has several clinical variations:^[4][6]

• Hypertrophic lichen planus: Thick, scaly, and very itchy lesions
• Atrophic lichen planus: A rare form with ring-shaped lesions that have an atrophic (thin) center
• Annular lichen planus: Lesions that develop in rings or circular patterns with central clearing
• Linear lichen planus: Lesions arranged in lines
• Lichen planopilaris: Affects the scalp and can cause permanent hair loss

How is lichen planus diagnosed?

Your healthcare provider will likely start by talking with you about your symptoms and medical history, followed by a physical examination. They will look closely at the affected areas of your skin, mouth, or other body parts.^[9]

In classic cases where the appearance is typical, lichen planus may be diagnosed based on the clinical presentation alone. However, because other conditions can look similar, additional testing is often helpful and sometimes required.^[6]

Biopsy

A biopsy is often recommended to confirm the diagnosis, especially in atypical cases. During this procedure, your healthcare provider removes a small piece of affected tissue for examination in a laboratory. The tissue sample is examined to see if it has the cell patterns typical of lichen planus. A 4-millimeter punch biopsy is commonly used for this purpose.^[6][9]

The microscopic examination typically reveals distinctive features, including a band-like infiltrate of immune cells in the upper layer of skin and damage to skin cells. Special testing called direct immunofluorescence may show deposits of certain immune proteins mixed with damaged skin cells.^[8]

Blood tests

Your healthcare provider may order blood tests to check for conditions associated with lichen planus, particularly hepatitis C virus infection. They should ask about risk factors for hepatitis C and order liver enzyme tests and hepatitis C antibody tests.^[6][9]

Treatment options

If you have no pain or discomfort, you may not need any treatment, as lichen planus on the skin often clears up on its own within months to years. However, medicines and other treatments can help relieve itching, ease pain, and speed healing.^[9]

Treatment choice depends on the severity of your condition and where the lesions appear. You may need more than one approach to control your symptoms, and you’ll likely need follow-up care with your healthcare provider at least once a year.^[9]

Topical corticosteroids

High-potency topical corticosteroids are the first-line treatment for all forms of lichen planus, including skin, genital, and oral lesions. These are prescription steroid creams or ointments that help reduce pain, swelling, and inflammation.^[6][9]

Commonly prescribed topical steroids include clobetasol, a very strong corticosteroid. When used as directed, these medications are safe and effective. For oral lichen planus, corticosteroid mouthwashes and sprays can help ease symptoms like burning or sore gums.^[5][9]

Systemic corticosteroids

If topical treatments don’t help and your condition is severe or widespread, your healthcare provider might suggest corticosteroid pills or injections. For severe, widespread lichen planus affecting oral, skin, or genital sites, oral prednisone therapy may be used for three to six weeks in a tapered course, typically starting at 30 to 60 milligrams per day.^[6]

For thick, raised lesions (hypertrophic lichen planus), injections of triamcinolone acetonide directly into the lesions may be effective.^[6]

Other topical treatments

Topical calcineurin inhibitors, such as tacrolimus and pimecrolimus, are used as second-line therapies to treat genital and oral lichen planus when corticosteroids are not effective or appropriate. These medications work differently from steroids but also reduce inflammation.^[6]

Oral medications

Several oral medications may be used for lichen planus:^[9]

• Antimalarial drugs such as hydroxychloroquine
• Antibiotics such as metronidazole
• Antifungal medicines like griseofulvin

Advanced treatments

For patients with severe lichen planus that does not respond to topical treatment, referral to a dermatologist for systemic therapy may be necessary. Options include oral retinoids (such as acitretin) or immunosuppressant medications. These treatments are more complex and require careful monitoring due to potential side effects.^[6]

Self-care and lifestyle tips

There are several things you can do at home to help ease symptoms of lichen planus, depending on which area of your body is affected.^[5]

For lichen planus on the skin

• Wash with warm water and avoid soaps and body washes that may irritate your skin
• When washing your hair, do so over a sink or bath so shampoo doesn’t touch the rest of your skin
• Use moisturizing treatments (emollients) prescribed by your healthcare provider
• Try not to scratch the affected areas, even though they may itch

For lichen planus on the genitals

• Take showers rather than baths when possible
• Hold a bag of frozen peas wrapped in a clean tea towel against affected areas to ease itching and swelling
• Avoid wearing tights or close-fitting clothes
• Carefully dry yourself after urinating to reduce contact between urine and your skin, avoiding rubbing the area
• Use a lubricant if sexual activity is painful

For lichen planus in the mouth

• Avoid salty, spicy, and acidic foods, or alcohol if they make your mouth sore
• Brush your teeth carefully twice a day to keep your gums healthy
• Use an alcohol-free mouthwash if regular mouthwash makes your mouth sore

What to expect

The natural course of lichen planus varies significantly from person to person. For most people with skin lesions, the condition clears up spontaneously within one to two years after it first appears. More than half of patients see their skin lesions resolve within six months, and 85% see resolution within 18 months.^[3][8]

However, recurrences are common, affecting about 20% of patients. After the lesions clear, they often leave behind skin discoloration (post-inflammatory hyperpigmentation) and occasionally hypertrophic scars, which may result from scratching.^[8]

Oral lichen planus tends to be more persistent and is generally a chronic condition. It may or may not improve over time and can sometimes become a lifelong condition. Treatment-induced improvement is typically followed by relapse, which is why doctors may not treat oral lichen planus if it causes no symptoms, due to the burden of treatment-related side effects.^[3][6]

Chronic cases are more likely when large, ring-shaped, or thick lesions are present, or when mucous membranes are involved. If the disease affects your mucous membranes and nails, it tends to be harder to treat, and even if treatment works, symptoms may return.^[9]

When medications trigger lichen planus (drug-induced lichen planus), the condition typically improves gradually after stopping the offending medication.^[3]

L43; L43.0; L443.1; L43.8; L43.9

Ruber planus, Lichen ruber planus

• Skin
• Oral mucosa (mouth)
• Scalp
• Nails
• Genitals