Lichen simplex chronicus

Definition:

A skin disorder characterized by chronic itching and scratching; the persistent scratching causes formation of thick leathery hyperpigmented skin patches. It is a type of neurodermatitis like atopic eczema.

Causes, incidence, and risk factors:

Lichen simplex chronicus is a localized form of atopic dermatitis. This is a skin disorder characterized by a self-perpetuating scratch-itch cycle. Although symptoms increase during times of emotional stress, there are physiological changes, including hypertrophy (enlargement) of the nerve fibers of a lesion (and loss of the basal cell margin).

Lichen simplex chronicus may be a result of something (such as clothing) that rubs or scratches the skin, or irritation of the skin causing the person to rub or scratch an area. This causes thickening of the skin as a response to chronic irritation. The thickened skin itches, causing more scratching, causing more thickening. The skin may become leathery. The disorder may cause brownish pigmentation of the skin in the lesion area.

This disorder may be associated with psoriasis. It may also be associated with nervousness, anxiety, depression, and other psychologic disorders. It can be 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.