Lichen Planus: Skin, Mouth and Nail Symptoms Explained

Lichen planus is an inflammatory condition, thought to be driven by the immune system, that causes itchy, flat topped, purple or dark bumps on the skin and lacy white patches or painful sores inside the mouth, and it can also affect the nails, scalp and genitals. It is not contagious, skin lichen planus often settles within one to two years, and treatment can ease itching and soreness, while oral lichen planus tends to last longer and needs regular check ups.

In India, lichen planus is commonly seen on the wrists, shins and ankles, and also as a pigmented form that causes dark patches on the face and neck. Because it can look like eczema, psoriasis, fungal infection or even pigmentation, a dermatologist’s diagnosis is important.

What does lichen planus look like on the skin?

Classic features:

• Small, flat topped, shiny bumps, often with angular edges
• Purple, violet or dark brown colour on Indian skin, sometimes almost black
• Fine white lines on the surface of the bumps, called Wickham striae, which can be seen up close
• Itching, sometimes intense
• Common on the inner wrists, forearms, ankles, shins, lower back and around the genitals
• New bumps in lines along a scratch or injury, which doctors call the Koebner phenomenon

Thick, warty patches on the shins (hypertrophic lichen planus) are very itchy and can last for years.

When the bumps settle, they often leave dark brown or grey patches, which may take months or longer to fade on brown skin. Our guide on post inflammatory hyperpigmentation explains why this happens.

What does oral lichen planus look like?

Lichen planus in the mouth is common, and some people have only mouth involvement.

• Lacy, white, web like lines on the inside of the cheeks, tongue or gums, often on both sides
• Red, raw or eroded patches, which can be painful
• Burning or sensitivity with spicy food, hot drinks, citrus or toothpaste
• Peeling or sore gums

The white lacy type may cause no symptoms and is often noticed by a dentist. The erosive type is painful and can make eating difficult.

Can lichen planus affect nails, scalp and genitals?

Yes:

• Nails: thinning, ridges, splitting, and in some cases permanent nail damage or loss. Early treatment may help protect the nail.
• Scalp: lichen planopilaris causes redness and scaling around hair follicles and patchy hair loss that can scar and become permanent. This needs prompt attention. See our guide on hair fall in women for other causes of hair loss.
• Genitals: purple bumps or white patches on the penis, or painful erosions on the vulva and vagina in women, which can cause scarring if untreated.

What is lichen planus pigmentosus?

Lichen planus pigmentosus is a variant seen more often in Indian and other brown skinned people. It causes slate grey, brown or blue grey patches, usually on the face, neck, and skin folds such as the underarms, often without the typical bumps. It is commonly confused with melasma or with dark patches from cosmetics. Some cases have been linked to mustard oil, hair dyes, and other substances applied to the skin, although this is not proven in every person. Our article on melasma treatment for Indian skin covers another common cause of facial pigmentation.

What causes lichen planus?

The exact cause is not fully understood. It is thought to be an immune reaction in which the body’s own immune cells attack the skin or mucous membrane cells. Possible triggers and associations include:

• Certain medicines, such as some blood pressure, anti malarial, anti inflammatory and other drugs, causing a lichenoid drug eruption
• Hepatitis C infection in some people
• Dental materials such as metal fillings, for some oral cases
• Stress, which may contribute to flares in some people

Lichen planus is not caused by poor hygiene, diet or infection that spreads to others.

How is lichen planus diagnosed?

A dermatologist can often recognise lichen planus from its appearance. A small skin biopsy may be advised to confirm it, especially in unusual forms, mouth or genital lesions, or to rule out other conditions. Your doctor may also ask about medicines and suggest blood tests, such as for hepatitis C, depending on your history.

Condition	How it differs
Lichen planus	Flat topped purple or dark bumps, white lines, itchy, wrists and shins
Psoriasis	Thicker plaques with silvery scale, elbows, knees, scalp
Eczema	Dry, rough, poorly defined itchy patches, skin creases
Ringworm	Ring shaped patches with a scaly, active edge
Melasma	Brown patches on cheeks and forehead, no bumps

If your rash looks more like thick scaly plaques, see our guide on psoriasis symptoms and treatment.

How is lichen planus treated?

Mild lichen planus that does not cause symptoms may not need treatment. The aim of treatment is to reduce itching, pain and inflammation, and to limit scarring and dark marks.

Depending on the type and severity, your dermatologist may consider:

• Prescription anti inflammatory creams or ointments for skin patches, used for a defined period under supervision
• Medicated gels, pastes or mouthwashes for oral lichen planus
• Injections into thick patches in selected cases
• Antihistamines to help with itching and sleep
• Phototherapy for widespread skin disease
• Oral medicines that calm the immune system for widespread, severe, scalp, nail or erosive disease
• Stopping or changing a medicine if a drug is thought to be the trigger, only with the advice of the prescribing doctor

Please do not use steroid creams from the chemist for long periods on your own, especially on the face or genitals. Our article on topical steroid misuse explains the risks.

What self care helps oral lichen planus?

• Avoid tobacco in all forms, including gutka, paan masala, khaini and smoking, and avoid areca nut (supari).
• Limit alcohol.
• Avoid foods that trigger pain, such as very spicy food, hot drinks, citrus and crisp, sharp foods, during flares.
• Use a soft toothbrush and a mild toothpaste without strong flavours if your mouth is sensitive.
• Keep regular dental check ups and maintain good oral hygiene.
• Report any new lump, ulcer that does not heal, or change in the patches to your doctor or dentist promptly.

How long does lichen planus last?

It varies a great deal:

• Skin lichen planus often settles within about one to two years, though it can come back.
• Thick lichen planus on the shins and oral lichen planus tend to last longer, sometimes for many years, with flares and quieter periods.
• Dark marks left behind on brown skin may take months or longer to fade after the active bumps have settled.

Because the course is unpredictable, regular follow up with your dermatologist helps adjust treatment over time.

When to see a dermatologist

See a dermatologist if:

• You have itchy, purple or dark flat bumps on the skin.
• You notice white lacy patches or painful sores in the mouth.
• Your nails are thinning, splitting or being lost.
• You have patchy hair loss with redness or scaling on the scalp.
• You have sore patches or itching in the genital area.
• An ulcer or patch in the mouth does not heal or changes.
• A rash began after starting a new medicine.

Lichen planus can be frustrating, but with the right diagnosis and treatment it is usually manageable. Dr. Maria offers online consultations to assess your symptoms and photos, discuss treatment, and advise when an in person examination or biopsy is needed.