Lichen Planus: Symptoms, Causes, and UK Treatment Options

Lichen planus is a relatively common inflammatory condition that affects the skin and sometimes the mucous membranes (such as the mouth or genitals). In the UK, it is estimated to affect approximately 1% of the population. It is characterised by a rash of flat-topped, firm, purple-red bumps that can be intensely itchy.

Unlike many other rashes, lichen planus is not an infection. It is an autoimmune-mediated condition, meaning your body’s immune system mistakenly attacks the skin cells. It is not contagious, nor is it a sign of poor hygiene. While the rash can look alarming, it is usually benign, though it can cause significant discomfort due to the itching.

Identifying lichen planus involves looking for the 'six Ps': planar (flat-topped), purple, polygonal (irregular edges), pruritic (itchy), papules, and plaques. The rash often has a distinctive look that distinguishes it from eczema or psoriasis.

• Appearance: Shiny, flat-topped bumps that are usually purple or dusky pink.
• Wickham’s Striae: If you look closely or use a magnifying glass, you may see fine white lacy lines on the surface of the bumps.
• Location: It most frequently appears on the inner wrists, ankles, lower back, and shins.
• Itching: The itch can be severe, often worse at night, and unlike eczema, scratching the bumps does not usually cause them to bleed, but it can trigger new bumps to form (known as the Koebner phenomenon).
• Mouth and Nails: In about 50% of cases, white lacy patches appear inside the cheeks. Nails may become thinned, ridged, or split.

According to NHS and NICE guidance, the exact cause of lichen planus remains unclear. However, it is widely accepted as an immune system disorder where T-cells attack a protein in the skin. Factors that may trigger or worsen the condition include:

• Stress: Emotional stress is a frequently cited trigger for flare-ups.
• Medications: Certain medicines for high blood pressure, heart disease, or arthritis can cause a 'lichenoid' reaction.
• Viral infections: There is some evidence linking lichen planus to Hepatitis C, though this is less common in the UK.
• Metallic fillings: In cases of oral lichen planus, some patients may have a sensitivity to mercury in amalgam fillings.

In many cases, lichen planus will clear up on its own within 6 to 18 months. However, if the itching is distressing or the rash is widespread, treatment is focused on reducing inflammation and easing the itch.

Topical Corticosteroids

Strong steroid creams or ointments (such as betamethasone or clobetasol) are the first-line treatment recommended by NICE. These are applied directly to the papules to reduce swelling and redness.

Antihistamines

While they don't treat the rash itself, sedative antihistamines taken at night can help patients sleep if the itching is particularly intense.

Immunomodulators

For sensitive areas like the face or skin folds, non-steroid creams like tacrolimus may be prescribed by a specialist to avoid the skin-thinning side effects of long-term steroid use.

Phototherapy

In severe or widespread cases, a dermatologist may recommend ultraviolet (UV) light therapy to help calm the immune response in the skin.

While waiting for treatment to take effect, there are several steps you can take at home to manage the symptoms:

• Avoid scratching: Scratching can damage the skin and lead to secondary bacterial infections.
• Cool compresses: Applying a cool, damp cloth to the affected area can provide temporary relief from itching.
• Moisturise: Using a plain, fragrance-free emollient can keep the skin hydrated and reduce irritation.
• Dietary changes (Oral): If you have mouth involvement, avoid spicy, acidic, or salty foods that can sting the lacy patches.
• Stress management: Practices such as mindfulness or yoga may help reduce the frequency of flare-ups.

If you notice a new, itchy purple rash, it is important to seek a professional diagnosis to rule out other conditions. You can speak to a GP online via OnlineDoctor24 for a convenient assessment. During a video consultation, the doctor can examine the rash, discuss your medical history, and determine if the symptoms match lichen planus.

An online GP can provide a private prescription for high-potency steroid creams that are not available over the counter. If the diagnosis is uncertain or the condition is not responding to standard treatment, they can also provide a referral to a dermatologist for further investigation, such as a small skin biopsy.