Lichen Planus Types, Symptoms, and Options for Treatment

Lichen planus (LP) is a chronic inflammatory disease that can affect different parts of the body, including the skin, scalp, nails, and mucous membranes. Cutaneous LP causes itchy, purplish lesions on the skin that tend to clear on their own without treatment. Mucosal LP causes lesions in the mouth that tend to be long-lasting and difficult to treat.

Lichen planus can be diagnosed with a physical exam, a review of your medical history, and, if needed, a tissue biopsy. There is no cure for LP, but topical or oral steroids can help bring the symptoms under control.

Types and Symptoms

There are several types of lichen planus that vary by the parts of the body they affect. They also differ by the symptoms and complications a person may experience, including the risk of cancer.

Cutaneous Lichen Planus

Cutaneous LP affects the skin. It is characterized by flat, purplish lesions that develop over several weeks. Scaly patches and itching, sometimes extreme, are also common. After the rash clears, the skin may be darker than normal (known as post-inflammatory hyperpigmentation).

Parts of the body commonly affected by cutaneous LP include:

• Face
• Nape of the neck
• Arms
• Back of the hands
• Palms and soles
• Skin folds, such as the armpits and groin (referred to as inverse lichen planus)
• Scalp (referred to as lichen planopilaris), often leading to patchy hair loss
• Nails, causing the thinning, splitting, ridging, and discoloration of fingernails or toenails

Mucosal Lichen Planus

Mucosal lichen planus is a form of the disease affecting mucous membranes. Although the disease can affect any mucosal tissue in the body, the mouth is predominantly affected.

Mucosal LP is characterized by the appearance of white lacy patches called Wickham's striae, as well as open sores (ulcers) and blisters (bullae) that can be painful.

The three main types of mucosal lichen planus include:

• Oral lichen planus (OLP): This causes Wickham's striae on the tongue, gums, and cheeks. There may also be ulcers (referred to as ulcerative OLP), inflamed gums (atrophic OLP), and blisters (vesiculobullous OLP). Sensitivity to hot or spicy food is also common.
• Genital lichen planus: This less common variation affects the head of the penis or the skin of the scrotum in males, and the vulva or vagina in females. Extreme itchiness and pain with sex are also common.
• Esophageal lichen planus: This uncommon variation affects the esophagus (feeding tube), causing pain with swallowing and difficulty swallowing.
  

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Causes

Lichen planus is most commonly seen in people between the ages of 30 and 60. Women are more frequently affected than men.

The cause of lichen planus is unknown. However, it is largely believed to be an autoimmune disease wherein the body's immune system mistakenly attacks normal tissues with inflammation.

Some experts believe that the autoimmune response may be triggered by certain viruses, like the hepatitis C virus (HCV). In some people, the antibodies produced by HCV may mistakenly identify normal cells found in the skin and mucosal tissues, called keratinocytes, as the virus.

This is evidenced by research that showed that people with LP are five times more likely to test positive for HCV, while people with HCV are up to five times more likely to develop LP.

Lichen planus has also more recently been linked to certain medications such as:

• ACE inhibitors like Lotensin (benazepril)
• Antimalarial drugs like chloroquine
  
• Beta-blockers like Tenormin (atenolol)
• Gold-containing drugs like Myocrisin (sodium aurothiomalate)
• Thiazide diuretics like chlorthalidone
• Nonsteroidal anti-inflammatory drugs (NSAIDs) like Aleve (naproxen)
• Tumor necrosis factor-alpha (TNF-a) inhibitors like Humira (adalimumab)

Stress is also a risk factor that frequently precedes the outbreak of an LP rash.

Diagnosis

Lichen planus is usually diagnosed based on the symptoms and the exclusion of all other possible causes. There is no single test available that can diagnose LP on its own.

The diagnosis would start with a review of your medical history and a physical exam of the affected area. Your provider would also want to query any medications you've taken that may have coincided with the rash outbreak.

A tissue biopsy may help confirm the diagnosis. This may be obtained with a simple punch biopsy (using a paper punch-like device). For esophageal LP, a sample of tissue can be obtained while viewing the esophagus with a lighted scope, known as endoscopy.

When viewed under the microscope, the tissue sample would show abnormally thick and irregular layers, often in a "sawtooth" pattern. There would also be areas with dead keratinocytes.

Other tests may be ordered to rule out conditions that mimic LP, such as:

• Drug skin eruption
• Psoriasis
• Atopic dermatitis
• Cutaneous lupus erythematosus
• Discoid lupus erythematosus
• Allergic contact mucositis
• Desquamative gingivitis
• Leukoplakia
• Oral squamous cell carcinoma 
• Oropharyngeal candidiasis

Treatment

There is no cure for lichen planus. Although cutaneous and oral LP are caused by the same underlying mechanism, they are often treated in very different ways.

Cutaneous Lichen Planus

Most cases of cutaneous LP will spontaneously clear without treatment within six months to a year. The treatment, if any, is focused on alleviating itching and scratching that can prolong symptoms.

Treatment options include:

• Antihistamines like Zyrtec (cetirazine)
• Mid- to high-potency topical corticosteroids (steroids) like betamethasone
  
• Oral corticosteroids like prednisone
• Corticosteroid injections, like triamcinolone
• Oral retinoids, like isotretinoin and acitretin
• Ultraviolet A (UVA) light therapy

With drug-induced LP, all that may be needed is the discontinuation or substitution of the offending drug.

Mucosal Lichen Planus

Unlike cutaneous LP, mucosal LP can be hard to treat and may persist for five years or more even with treatment. Treatment is considered essential because the prolonged duration of symptoms can increase the risk of oral cancer.

The treatment is largely focused on avoiding alcohol, smoking, and spicy or acidic foods that can make symptoms worse. In addition, certain medications may be prescribed to help temper the overactive immune response, including:

• Very-high-potency topical corticosteroids like clobetasol 
• Oral corticosteroids like prednisone
• Topical calcineurin inhibitors like Elidel (pimecrolimus) 

Prognosis

Lichen planus is a chronic condition that can come and go in episodes lasting anywhere from weeks to years. In most cases, LP is not life-threatening. However, severe cases have been known to cause permanent scarring and hair loss.

Moreover, among people with oral LP, between 1% and 4% will develop oral cancer. For this reason, people with oral LP should be checked for signs of cancer every six to 12 months. Smoking cessation and a reduction in alcohol use are also recommended to lower the cancer risk.

Cutaneous LP is not associated with an increased risk of skin cancer.

Summary

Lichen planus is a chronic inflammatory and autoimmune disease that affects the skin, nails, hair, and mucous membranes. It causes flat, itchy, purplish lesions on the skin (cutaneous LP) or white lacy patches or sores in the mouth (oral lichen planus).

LP is diagnosed based on your symptoms and may be confirmed with a biopsy. Cutaneous LP tends to clear on its own within weeks, months, or years. Oral LP is often difficult to treat and may persist for years even with high-potency corticosteroids.