Definition of Lichen simplex chronicus:

Lichen simplex chronicus is a skin disorder characterized by chronic itching and scratching. The constant scratching causes thick, leathery, brownish skin.

Causes, incidence, and risk factors:

This is a skin disorder characterized by a self-perpetuating scratch-itch cycle:

• It may begin with something that rubs, irritates, or scratches the skin, such as clothing.
• This causes the person to rub or scratch the affected area. Constant scratching causes the skin to thicken.
• The thickened skin itches, causing more scratching, causing more thickening.
• The skin may become leathery and brownish in the affected area.

This disorder may be associated with atopic dermatitis (eczema) or psoriasis. It may also be associated with nervousness, anxiety, depression, and other psychologic disorders.

It is common in children, who chronically scratch insect bites and other areas. It can also be common in mentally retarded children who have chronic repetitive movements.