Lichen planus is a non-infectious skin condition which mainly affects older people (over 40). It develops in 2% of the world’s population and takes the form of an itchy skin rash which affects several parts of the body.
This condition affects both men and women although women are more prone to developing the oral version. Lichen planus is not inherited and cannot be transmitted to other people.
Causes of lichen planus
This condition is caused by:
- Reaction to certain types of medication
- Autoimmune reaction in your body
There are some medications which trigger this reaction, for example anti-malarial tablets and arthritis injections (disease modifying anti-rheumatic drugs). Both of these cause this itchy skin rash.
An autoimmune reaction is where your body’s immune system goes into overdrive, releasing an excess amount of proteins into your bloodstream. These proteins cause an inflammation in the skin and a rash.
Symptoms of lichen planus
The most obvious sign is an itchy skin rash which develops on the skin, inside the mouth and around the genitals. It can affect other areas such as the scalp or nails although this is less common.
Women are more likely to develop this rash inside the mouth compared to men.
The type of rash you develop depends upon what part of the body it appears on.
Lichen plan (Mouth)
For example, a rash inside the mouth (oral lichen planus) consists of red and white patches on the tongue and inside the cheeks and painfully sore gums. Mouth ulcers also develop.
Lichen planus (skin)
A rash which develops on the skin consists of small red or purple pustules which are slightly raised and may contain white marks. These pustules mainly affect the arms, legs and wrists although they can appear elsewhere.
Lichen planus (genitals)
Lichen planus may develop around the genital area: this includes the penis for men and the vagina for women.
The male version consists of purple or red patches or pustules on the head of the penis. This rash is not itchy.
The female version develops on both the vulva and vagina and takes the form of a red, sore rash which is raw in places and may contain white streaks. It can cause the discharge of a yellow or green fluid which may contain blood.
Sex is painful for both men and women who are affected by this condition.
Diagnosing lichen planus
Your GP will examine the area of your body affected by this condition and may make a diagnosis based on this. If you have the oral version of lichen planus then this can be diagnosed by your dentist.
But if your GP is uncertain as to the cause of your rash, because it looks similar to other skin conditions such as eczema then he/she will perform a skin biopsy. This is the removal of a small section of skin which is sent to a laboratory for analysis. This procedure is carried out under a local anaesthetic.
Treatment for lichen planus
Lichen planus cannot be cured so the aim is to manage the symptoms. Medication will be given to clear the rash.
Mild cases do not require any treatment. But other cases will need some form of help, for example, corticosteroid creams and tablets. Another option is an antihistamine or light therapy.
You may be referred to a dermatologist depending upon the severity of your symptoms.