Lichen simplex chronicus involves a cycle in which scratching provokes itching, which provokes more scratching.
It most often affects skin areas that are easier to reach, such as the upper chest, arms, neck, legs, and genital area, and often does not affect skin areas that are more difficult to reach, such as the mid to upper back.
Corticosteroids applied to the skin and measures to relieve itching help, but people should avoid scratching and rubbing the skin.
(See also Overview of Dermatitis Overview of Dermatitis Dermatitis is inflammation of the upper layers of the skin, causing itching, blisters, redness, swelling, and often oozing, scabbing, and scaling. Known causes include dry skin, contact with... read more .)
Lichen simplex chronicus is caused by chronic scratching or rubbing 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 Contact Dermatitis Contact dermatitis is skin inflammation caused by direct contact with a particular substance. The rash may be itchy, is confined to a specific area, and often has clearly defined boundaries... read more or other condition, but the person continues to scratch long after the inciting cause is gone. This persistent itch may involve changes in the way a person's nervous system perceives and processes itchy sensations. Lichen simplex chronicus frequently occurs in people who have anxiety disorders and emotional stress. People who have atopic dermatitis Atopic Dermatitis (Eczema) Atopic dermatitis (commonly referred to as eczema) is chronic, itchy inflammation of the upper layers of the skin that often develops in people who have hay fever or asthma and in people who... read more , hay fever Seasonal Allergies Seasonal allergies result from exposure to airborne substances (such as pollens) that appear only during certain times of the year. Seasonal allergies cause itchy skin, a runny nose, sneezing... read more , and asthma Asthma Asthma is a condition in which the airways narrow—usually reversibly—in response to certain stimuli. Coughing, wheezing, and shortness of breath that occur in response to specific triggers are... read more or who have only atopic dermatitis are particularly susceptible to developing lichen simplex chronicus given their predisposition to itch.
Lichen simplex chronicus can occur anywhere on the body, including the anus (see Pruritus Ani Anal Itching Itching of the anus (the opening at the end of the digestive tract where stool leaves the body) and the skin around the anus (perianal skin) is called anal itching or pruritus ani. (See also... read more ) and the genital area (pruritus of the vulvae or scrotum—see Genital Itching Genital Itching Genital itching may involve the vagina or the genital area (vulva), which contains the external genital organs. Itching is an unpleasant sensation that seems to require scratching for relief... read more ). In the early stages, the skin looks normal, but it itches. Later, dryness, scaling, thickening, and dark patches develop as a result of the chronic scratching and rubbing. This process, called lichenification, causes the skin to resemble leather.
Doctors base the diagnosis of lichen simplex chronicus on the results of a physical examination and sometimes take samples of skin and send them to a laboratory (biopsy Biopsy Doctors can identify many skin disorders simply by looking at the skin. A full skin examination includes examination of the scalp, nails, and mucous membranes. Sometimes the doctor uses a hand-held... read more ). Doctors try to discover any possible underlying allergies or diseases that may be causing the initial itching.
When severe itching occurs around the anus or genital area, the doctor may investigate the possibility of other causes, such as
If a cause for the itch can be identified, it is treated.
A potent corticosteroid ointment is applied to the area. People can increase the effects of the corticosteroid ointment by covering the area with plastic wrap and leaving it on overnight. Commercial surgical tape products that are saturated with a corticosteroid help relieve itching and inflammation and protect the skin from scratching. For small areas, the doctor may inject longer-acting corticosteroids under the skin to control the itching.
Doctors may give antihistamines by mouth. Moisturizing agents (emollients) and capsaicin cream may also be applied to the affected areas.
When this disorder develops around the anus or genital area, the best treatment is a corticosteroid cream.