Lichen planus is an inflammatory skin condition that causes a rash that is usually itchy. It consists of small, shiny, slightly raised, flat-topped bumps that can be pink or purple in color.
Lichen planus can develop anywhere on the body but often affects the wrists, lower back, and ankles. It is not contagious.
This article explains what lichen planus is and outlines its symptoms, causes, and treatment options. It also looks at a person’s outlook and when to contact a doctor.
Lichen planus is an inflammatory condition with no known cause that can affect the skin and the inside of the mouth.
When it develops on the skin, it causes a rash that is usually itchy. This is called cutaneous lichen planus. When it develops in the mouth, it is called oral lichen planus, and a person can experience burning or sore sensations.
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Types
There are different types of lichen planus, including:
- cutaneous lichen planus, which affects the skin
- mucosal, which affects the mucous membranes, such as the inside of the mouth
- lichen planopilaris, which affects the scalp
- lichen planus of the nails
A lichen planus rash can also develop as a result of some medications. Healthcare professionals call this lichenoid drug eruption.
Symptoms vary depending on the site of the condition. The American Academy of Dermatology outlines the following symptoms:
Cutaneous lichen planus
When lichen planus develops on the skin, a person will develop bumps that are slightly raised, shiny, firm, and reddish-purple in color.
These bumps often measure 3–5 millimeters in diameter and can have small white lines running through them, called Wickham’s striae.
It most commonly develops on the wrists, lower back, and ankles. However, it can also affect the:
- scalp
- arms
- legs
- genitals
A person can experience:
- thick patches of skin that are rough and scaly
- itching
- pain, particularly if the rash affects the genitals
- blisters, although this is less common
When the rash develops on the legs, the bumps are typically darker in color. It is also possible to develop painful sores on the genitals.
Oral lichen planus
Oral lichen planus most commonly affects the inside of the cheeks, but it can also affect the tongue, lips, and gums.
A person may develop:
- patches of small white dots and lines that have a lace-like appearance
- swelling
- redness
- peeling
- painful sores
Lichen planopilaris
A person with lichen planus on the scalp may experience:
- skin inflammation
- irritation
- tiny bumps
- thinning of the hair
- patches of hair loss
Hair loss associated with lichen planus
Lichen planus affecting the nails
When lichen planus affects the nails, a person may experience:
- ridges or grooves that develop on the nails
- nails that split or become thin
- nail loss
Nail loss can be temporary or permanent.
Lichen planus affecting the genitals
Those with a penis may develop bumps and white streaks that appear in a ring around the glans of the penis.
Lichen planus may affect the labia majora, labia minora, and the external opening of the vaginal canal. A person may experience:
- painless white streaks in a lacy pattern
- ulcers that are painful and persistent
- painful vaginitis, which can cause a vaginal discharge and pain
Scarring can also occur.
The exact cause of lichen planus is unclear.
Lichen planus may develop due to — or have associations with — the following:
- physical and emotional stress
- injury to the skin
- skin diseases, such as herpes zoster
- viral infections, such as hepatitis C
- contact allergy to mercury metal fillings or chemicals used in color photographic development
- vitamin D deficiency
Medications can also cause lichen planus. These include:
- antimalarials
- thiazide diuretics
- nonsteroidal anti-inflammatory drugs
- beta-blockers
- gold
- tumor necrosis factor (TNF)-alpha inhibitors
- angiotensin-converting enzyme inhibitors
Risk factors
Lichen planus can affect people of any age or race. However, it is
A healthcare professional can often diagnose lichen planus by looking at the skin, nails, and mouth.
They may perform a biopsy to confirm the diagnosis, which involves removing a section of the skin and examining it under a microscope.
In some cases, blood tests may be required to rule out other conditions.
Lichen planus is not a curable condition. Treatment focuses on easing symptoms until the rash clears.
Mild cases require no treatment by the doctor, except for occasional checkups. Treatment for more severe cases of lichen planus may include the following:
- antihistamines to relieve itching
- topical corticosteroid creams or ointments to relieve swelling and inflammation
- systemic corticosteroids to help treat long lasting lichen planus
- PUVA therapy, which is a light treatment
- retinoic acid, which a person can take in the form of a pill or apply directly to the skin
- tacrolimus ointment and pimecrolimus cream
To treat oral lichen planus, a healthcare professional can prescribe topical treatments, such as mouthwashes and sprays, to apply to the sores or medications a person takes in the form of a pill.
Alongside the prescribed treatment options, a person can ease the symptoms of lichen planus at home with the following measures:
Cutaneous lichen planus
A person can try:
- using warm water to wash and avoiding soaps and body washes
- washing their hair over the sink so the shampoo does not touch the rest of the skin
- applying a cool cloth to relieve itching or taking a colloidal oatmeal bath
- avoiding scratching
- applying an emollient moisturizing treatment, if a doctor prescribes it
Oral lichen planus
People should consider maintaining good oral hygiene, such as:
- brushing their teeth twice daily
- flossing each day
- using an alcohol-free mouthwash
- visiting the dentist twice a year
People should avoid:
- alcohol
- foods that are spicy, salty, and acidic
- smoking and chewing tobacco
Lichen planus on the gentials
If a person has lichen planus on their genitals, they can try:
- showing instead of using a bath
- applying a cold compress, such as a bag of frozen peas wrapped in a clean tea towel, to relieve itching and swelling
- carefully drying the skin after urinating and avoiding rubbing the area
- using a lubricant if sex is painful
It is also best to avoid wearing tights or close-fitting clothes.
The following can worsen symptoms of lichen planus, depending on its location:
- stress
- scratching the rash
- smoking, chewing tobacco, or drinking alcohol
- eating certain foods, including:
- spicy foods
- citrus fruits
- tomatoes and foods made with tomatoes
- crispy and salty snacks
- caffeinated beverages
According to a
Cutaneous lichen planus often resolves without treatment within 1–2 years. However, recurrence is common, and the rash can cause hyperpigmentation.
Oral lichen planus may resolve within 5 years. However, it is more likely to be chronic and may return.
Erosive lichen planus
Erosive lichen planus is a long lasting form of the condition. It causes painful ulcers to develop and may cause discomfort and burning on the genitals.
In 2% of cases, long-term erosive lichen planus may develop into types of cancer, such as oral cancer, vulval cancer, and penile cancer.
The following are commonly asked questions about lichen planus.
Is lichen planus an autoimmune condition?
Healthcare professionals consider lichen planus to be an autoimmune condition that causes inflammatory cells to attack a protein in the skin and mucus membranes.
What is the difference between lichen planus and lichen sclerosis?
Lichen planus is an inflammatory skin condition that affects the skin and mucous membranes. Lichen sclerosis is also a skin condition, but it most commonly affects the genital and anal areas.
It is possible that they are both autoimmune conditions.
What is the difference between lichen planus and psoriasis?
Lichen planus and psoriasis are both autoimmune conditions that cause rashes to appear on the skin. However, they are entirely different medical conditions.
Psoriasis causes the skin cells to multiply too quickly, resulting in patches of skin that become scaly and inflamed.
Is lichen planus contagious?
Lichen planus is not contagious.
Can I prevent lichen planus?
It may not be possible to prevent lichen planus. However, a person can take steps to help prevent symptoms from worsening.
A person may wish to contact a healthcare professional if they notice any signs and symptoms of lichen planus. A healthcare professional will be able to diagnose the condition and help treat its symptoms.
Lichen planus is an inflammatory skin condition that causes a rash on the skin and mucous membranes. The rash consists of small bumps that can develop on the torso, arms, legs, scalp, and genitals. It can also affect the nails.
Although the cause is not known, healthcare professionals consider it to be an autoimmune condition.
There is no cure, but the rash usually resolves without treatment. A healthcare professional can suggest treatment options to help manage the symptoms in the meantime.