Lichen simplex chronicus

[Greta]

Lichen simplex chronicus is chronic, itchy inflammation of the top layer of the skin.

Lichen simplex chronicus involves a cycle in which scratching provokes itching, which provokes more scratching.
It most often affects the head, arms, neck, and legs.
Corticosteroids applied to the skin can help, but the most important treatment is to stop scratching.

(See also Overview of Dermatitis.)
Lichen simplex chronicus is caused by chronic scratching of an area of skin. The act of scratching triggers more itching, beginning a vicious circle of itching-scratching-itching.
Sometimes the scratching begins for no apparent reason. Other times scratching starts because of a chronic dermatitis or other condition, but the person continues to scratch long after the inciting cause is gone. Doctors do not know why this happens, but psychologic factors may play a role. The disorder does not seem to be allergic. It usually develops between the ages of 20 and 50.