Lichen planus is a skin disease. It mostly appears as purple or reddish-purple bumps on the skin. Lichen planus may cause a small number of skin lesions or less often affect a wide area of the skin and mucous membranes. In 85% of cases it clears from skin surfaces within 18 months but it may persist longer especially when affecting the mouth or genitals. Lichen planus generally occurs at or after middle age. It is less common in children. The initial attack may last for weeks to months and then recur for years. Women are affected somewhat more than men; the majority of sufferers are between the ages of 30 and 60. Oral lichen planus is an inflammatory condition affecting the lining of the mouth. It occurs most often on the inside of the cheeks, but can affect the gums, tongue, lips and other parts of the mouth. Occasionally oral lichen planus involves the throat or the esophagus.
Possible causes of oral lichen planus include non-steroidal, anti-inflammatory drugs, iodides, tetracycline, gold, streptomycin, hydrochlorothiazide, dental fillings containing mercury in the form of amalgam and rough fillings. People who have lichen planus in the mouth may be allergic to certain medications, ingredients in candy or gum, or products used during dental procedures. Lichen planus is not contagious.
A type of inflammation develops in the skin which causes the rash. However, the cause of the inflammation is not known. One theory is that the immune system may be 'triggered' by a virus or other factor in the environment to attack cells on the skin which leads to the inflammation.
Signs and symptoms of lichen planus include:
- Rows of flat-topped bumps that may vary in color from purple to pink to red
- Itching, which may be severe
- Soreness or a burning sensation when involving the mucous membranes
- Grooving, splitting, thinning or nail loss when involving the nails
- Redness, irritation, hair thinning and hair loss when involving the scalp
- Ridges in the nails
- Dry mouth
- Metallic taste in the mouth
Prolonged treatment may be needed during outbreaks of the rash. However, between outbreaks, no treatment is needed.
Topical retinoic acid cream and other ointments or creams may reduce itching and inflammation and may aid healing. Occlusive dressings may be placed over topical medications to protect the skin from scratching.
When extensive parts of the body are affected then stronger treatments are necessary and these are usually supervised by a hospital specialist. This may be tablets or on occasion ultra-violet light therapy.
Your dermatologist may have to make sure that the sores are not caused by yeast or an infection and are not canker sores. Sometimes, the biopsy tissue must be studied by a special technique and blood tests may be needed to rule out other oral diseases.