Lichen planus: treatment, symptoms, causes and how long it lasts

The NHS says creams and ointments from a GP can help control the rash and ease itching. If they do not work, or the lichen planus is severe, steroid tablets or light therapy can help. For the mouth, mouthwashes and sprays from a GP can ease burning or sore gums.

The BAD says treatment depends on the type of lichen planus, the severity of symptoms and any specific risks such as hair loss or nail damage. Mild lichen planus without symptoms often does not need treatment. It adds that there are no medicines developed specifically for lichen planus, and the medicines used are outside their product licence but have cumulative evidence that they help. These treatments control the condition rather than cure it.

The BAD describes lichen planus as an uncommon inflammatory condition that can affect the skin, mucous membranes (mouth, gums, vulva, vagina, penis), hair and nails. It can affect anyone and presents differently across people. Oral lichen planus is slightly more common.

The NHS lists conditions that look similar and are worth checking: psoriasis, pityriasis rosea, lichen sclerosus, ringworm and eczema. If the diagnosis is not clear, the BAD says a skin biopsy under local anaesthetic may be needed.

The NHS lists the main symptoms: clusters of shiny, raised, purple-red blotches on the arms, legs or body, often with fine white lines; white patches on the gums, tongue or insides of the cheeks; burning and stinging in the mouth, especially when eating or drinking; bald patches on the scalp; sore red patches on the vulva; rough, thinning nails with grooves; and ring-shaped purple or white patches on the penis. You may only have one of these.

The BAD adds that the typical skin rash is clusters of shiny, slightly raised pink or purple-red spots of 1 to 3 mm, usually on the insides of the wrists, around the ankles and on the lower back, and that it can appear in a line where skin has been scratched (Koebner response). In skin of colour the rash may be darker than the skin colour or have a purplish hue, still with fine streaks. About 50% of people with skin lichen planus have it in the mouth too, and after it clears, darker marks may persist for a long time.

The BAD says a precise cause is not well understood but it is thought to involve an abnormal immune response, in which the immune system attacks cells in the skin and mucous membranes. Several factors may trigger it, including viruses such as hepatitis C, hepatitis B, human herpes viruses and varicella zoster virus; substances in contact with the skin such as mercury, copper and gold, including those in tooth fillings; some medicines, such as certain tablets for high blood pressure and medicines for malaria, infections and depression; and stress and anxiety.

It is not hereditary, but the BAD says the tendency to get lichen planus can sometimes run in families, especially twins.

The NHS says lichen planus on the skin usually gets better on its own in about 9 to 18 months, and lichen planus in the mouth can last for several years. You cannot catch it, and it does not usually come back once it has cleared up.

The BAD says in most people lichen planus heals by itself and does not return, but some have recurrent episodes spaced months or years apart, and types affecting the scalp, nails, mouth or genitals can last for many years. Currently there is no cure; the aim of treatment is to control the condition, reduce symptoms, prevent spread and minimise damage. Hair loss from scalp lichen planus is usually permanent, and affected nails can sometimes become permanently scarred.

The NHS suggests things to do at home, depending on the area affected.

• Skin: wash with warm water and avoid soaps and body washes, wash your hair over a sink or bath so shampoo does not touch the rest of your skin, use any emollient a GP prescribes, and try not to scratch.

• Genitals: have showers rather than baths, hold a bag of frozen peas wrapped in a clean tea towel against the area to ease itching and swelling, avoid tights or close-fitting clothes, carefully dry yourself after peeing without rubbing, and use a lubricant if sex is painful.

• Mouth: avoid salty, spicy and acidic foods, or alcohol, if they make your mouth sore, brush your teeth carefully twice a day, and use a mouthwash without alcohol if it stings.

The BAD says there is a low risk of skin cancer (squamous cell carcinoma) developing in areas of persisting, severe lichen planus, such as hypertrophic lichen planus or erosive disease on mucous surfaces including the mouth and gums, vulva and vagina, and penis.

For that reason, persistent sores, a sore that changes, a lump or a non-healing ulcer in an affected area should be reviewed by a doctor rather than managed alone.

The NHS says to see a GP if you think you might have lichen planus. Mouth symptoms may also be seen by a dentist. Diagnosis is usually made by a doctor examining the rash, according to the BAD.

On the NHS a GP can diagnose and start treatment, with referral to dermatology, oral medicine or gynaecology for biopsy, difficult or erosive disease, or when stronger medicines are needed.

Private dermatology can speed access to a biopsy or specialist review. Because several of the medicines used are outside their product licence, as the BAD notes, it is reasonable to ask what the aim of each medicine is and what monitoring it needs.