The American Academy of Dermatology describes lichen planus as a common noninfectious disease that affects the skin and mouth. There is no cure for this disease, but many medications are available to help control the symptoms.
Lichen planus is characterized by small, flat-topped, angular bumps on the surface of the skin. They are shiny and reddish-purple in color. They can appear anywhere on the body, but they most often form on the neck, lower legs, back, ankles and inside the wrists and elbows. These bumps are often intensely itchy. Blisters occur in rare instances. Oral lichen planus leaves small white dots, lines and painful ulcers inside the mouth.
The reason for this skin disease is unknown, according to the American Osteopathic College of Dermatology. The website suggests that it is caused by more than one factor. Some of the potential risk factors include stress, infections and autoimmune disorders. One severe type of lichen planus is inherited.
The American Academy of Dermatology indicates that lichen planus of the skin and mouth usually do not require treatment. Topical and oral medications help soothe the pain of mouth ulcers, while corticosteroid creams and antihistamines control itching on the skin.