Lichen planus (lichen planus) – what is it?

Lichen planus, also known as lichen planus, is a skin disease that can also affect the mucous membranes. Typical of the disease are red papules on the skin that look like small nodules. What forms of lichen planus are there, how do you recognize lichen planus and what helps against it? You can find out that and more in this article.

What is lichen planus (lichen planus)?

The lichen planus – technically known as lichen planus – is an inflammatory disease of the skin and mucous membrane.  The disease belongs to the group of autoimmune diseases and can show various patterns of appearance. The course is usually chronic and not contagious. 

As the name of the skin disease already expresses, one sees characteristic changes in the skin with flat, mostly reddened papules (“nodules”) that have a polygonal shape. 

 

Causes: how does lichen planus develop?

The causes and development of this skin disease are unclear, there may be a connection with a previous infection with the viruses hepatitis B or C. 

As with any disease, antibodies against the foreign antigens, i.e. the foreign substances, are formed. 

In an autoimmune reaction, there is misinformation in the body’s own defense cells and they fight substances that actually belong to the body. In this case, a so-called immunological cross-reaction is suspected to be the cause, in which the foreign antigens of the hepatitis virus have a similar structure to the body’s own substances, which is why the body’s own cells are ultimately attacked. In this way, the chronic inflammation and the typical symptoms of lichen planus presumably occur.

Occasionally, lichen planus can also occur as a result of vaccination against hepatitis B. *

Most of those affected become ill between the ages of 30 and 60. Men are affected slightly more often than women.

What are the symptoms of lichen planus?

Characteristic of the lichen planus are the characteristic blisters on certain areas of the body, which can also be painful. The skin disease occurs in flares and is mainly accompanied by severe itching . 

Areas commonly affected by lichen planus are:

• Wrists on the flex side (i.e. the inside towards the palm)
• lower back
• back of the knee
• Lower leg on the extensor side (i.e. the “front edge” of the shinbone)
• Genital region
• Anal region

 

What does lichen planus look like?

The lichen planus manifests itself primarily in the form of flat, reddened vesicles, which are often polygonal in shape. They are sharply demarcated and may have a dent in their center. They are often clustered together in larger groups or unite to form plates. 

If the blisters or nearby areas are irritated, for example by scratching, the skin can become inflamed and new nodules can form – this effect is known as the Koebner phenomenon.

If the palms of the hands and fingernails are involved, the blisters have a wart-like appearance and can lead to growth disorders of the nail. The blisters can persist for months or years. 

Lichen planus: what forms are there? 

There are different types of lichen planus: The most common type is lichen planus with flat papules on the skin. The acute course is shown by a disordered distribution pattern of the blisters, which resemble a skin rash. Since a skin rash is also referred to as an exanthema, the name of the acute course is exanthemic lichen planus. This occurs more frequently when taking gold salts, antimalarials and beta-blockers . 

There are also other forms:

• In the form of lichen ruber verrucosus , nodular, large papules appear on the lower legs in particular. These can also lead to scarring.
• Lichen ruber acuminatus affects the hairy skin and is associated with mild itching and an acute skin rash. 
• Lichen ruber follicularis describes the infestation of the scalp with a tendency to scar and possible hair loss.

infestation of the mucous membrane

If the mucous membranes are affected, one speaks of a lichen ruber mucosae.  30 to 50 percent of patients with lichen planus have an infection of the mucous membranes.

So-called Wickham stripes can often be seen here, these can be on the blisters or can also occur as the only symptom without blisters. A white, striped pattern then appears on the mucous membranes, which cannot be stripped off when touched.

Typical sites in lichen ruber mucosae are: 

• Can
• Lips
• Tongue
• genital area
• Anus

If only the genital or anal region is affected, the clinical picture is called lichen ruber genitalis. If only the oral mucosa is affected, it is called oral lichen planus.  This form should be checked regularly by the doctor, as it can develop into a precancerous stage. 

Another change affecting the mucous membranes, which must be distinguished from lichen ruber, is leukoplakia. It is caused by chronic irritation of the respective areas, which lead to cornification and a white appearance. Unlike lichen planus, however, they do not itch and are painless. 

 

Differentiation from lichen ruber – further differential diagnoses

Lichen sclerosus et atrophicus – or  white spot disease – represents a separate clinical picture that also belongs to the group of chronic inflammatory skin diseases. The causes are not known here either. 

The clinical picture manifests itself through raised blisters, but they have an irregular and hardened character. The skin disease occurs mainly on the female pubic area, on the foreskin of the penis and in the anal area and is characterized by itching, pain and possible narrowing.

Lichen simplex chronicus or lichen chronicus vidal, also known as neurodermatitis circumscripta, is a skin disease with severe itching that predominantly affects middle-aged women. The underlying cause here is psychological stress. With this clinical picture, there is a chronic change in the skin with an increase in thickness and a coarse structure. 

Pityriasis rosea  is another clinical picture with an acute course and a skin rash that mainly occurs on the trunk of the body. 

Other diseases that can cause a skin rash that looks similar include shingles , psoriasis (psoriasis) or lupus erythematosus. However, a doctor can usually easily distinguish these diseases from lichen planus.

What can be done against lichen planus?

Treatment of lichen planus is primarily aimed at relieving the symptoms. If the mucous membranes are involved, mouth gels, adhesive pastes, or mouthwashes that contain numbing agents can help relieve the pain. 

Care should be taken to avoid irritation from spicy or acidic foods, alcohol and nicotine as much as possible. Good oral and dental hygiene also plays an important role – but too intensive dental care can worsen the clinical picture. Irritation of the skin by scratching, hot water when showering or similar should be avoided in any case. 

Another option is PUVA bath and cream therapy: This is local photochemotherapy, i.e. light therapy that uses UVA radiation and photosensitizers. Photosensitizers – such as methoxsalen – are substances that are applied to the affected areas and can be activated by light. This makes the desired area accessible to the UVA light waves. This therapy procedure is a common method for chronic skin diseases. 

In addition to the light therapy, which can be carried out several times a week, moisturizing creams can be applied, which at best also relieve the tormenting itching. You should follow the advice of your doctor in this regard. 

Home remedies for lichen planus?

Treatment with home remedies such as linseed oil is currently not recommended, as an inflammatory reaction may be increased. There is no therapeutic evidence for zinc ointment  , it may actually worsen the condition when applied to severely inflamed areas.

 

What medications are available to treat ringworm?

Lichen planus can be treated both locally (e.g. with the mouth creams mentioned or externally with ointments) and systemically (e.g. with tablets) – this applies to the therapy of the skin and mucous membranes. 

Local (i.e. locally applied) ointments for treating the skin usually contain anti-inflammatory substances such as  glucocorticoids. Antihistamines help to treat the itching , and homeopathic medicines can also be used as a supplement . 

In the case of severe courses or involvement of hair and nails, systemic therapy should be carried out. Here there is the possibility of using the so-called retinoids, which are vitamin A preparations. As with local therapy, glucocorticoids can also be used in tablet form, these serve to reduce inflammation and can also reduce the annoying itching. The local application can be done with so-called occlusive bandages  , the wound surfaces are tightly covered with plastic film.

If the therapy options described so far do not work, an alternative is an immunosuppressive ( i.e. suppressing the immune system ) therapy approach with ciclosporin  . This drug interferes with the production of immune cells and inhibits the development of inflammatory substances in the body. 

Is lichen planus curable?

In the majority of cases, lichen planus is harmless and heals within eight to twelve months (sometimes even without treatment). However, the pronounced itching can massively restrict and stress those affected, so that therapy should be carried out in any case.

After the lichen planus has healed, brown skin changes may remain on the affected areas or the skin may appear thinner. Recurrences – i.e. a recurrence of lichen planus – cannot be ruled out.