Psoriasis

What is psoriasis?

Psoriasis is a common skin problem. It causes a thick, rough, dry buildup of the outer layer of skin. The thick areas of skin are called plaques. They usually occur on the scalp, elbows, knees, and buttocks, but they can develop anywhere on the skin.

People of all ages can have psoriasis. It is not contagious.

What is the cause?

When you have psoriasis, your outer layer of skin makes new cells more rapidly than normal. The extra cells become thick plaques. No one knows exactly what causes psoriasis, but most researchers believe it is an immune system disorder.

You are more likely to have psoriasis if members of your family have it.

What are the symptoms?

The symptoms are rough, dry, thick areas of skin. Often the skin under the plaques is slightly red. The skin may or may not itch.

Most psoriasis occurs in patches. Sometimes, however, it appears as many small, droplike, scaly areas. This is called guttate or raindrop psoriasis and it often occurs on the back.

Psoriasis can affect your fingernails and toenails, causing them to have pits or dents in them. In severe cases the nails become thick and misshapen.

A few people also have arthritis or joint pain with psoriasis.

The symptoms of psoriasis can vary from mild to severe. They may worsen when you are upset, sick, or injured. Flare-ups of the problem may also occur when:

• You have a skin injury, such as a cut, burn, rash, or insect bite.
• You drink a lot of alcohol (more than 1 drink a day for women, more than 2 drinks for men).
• You have either very little exposure to sunlight or you have a severe sunburn.
• Your skin is exposed to constant friction, for example, from clothing.

The severity of the symptoms may change with the seasons. Psoriasis usually gets better when you spend more time out in the sun.

How is it diagnosed?

Your healthcare provider will examine your skin and nails. For more information or to confirm the diagnosis, your provider may do a skin biopsy. The biopsy is done by removing a small sample of your skin after the area has been numbed with an anesthetic. The tissue is examined in the lab to see if the problem is psoriasis or some other skin problem.

How is it treated?

Your treatment depends on your symptoms. The goal is to ease discomfort and slow the production of skin cells to prevent or reduce the buildup of plaque.

Your healthcare provider will recommend or prescribe a cream or ointment to rub on your skin. A variety of medicines are available, such as:

• steroid cream or ointment
• salicylic acid cream or ointment
• tar preparation (commonly ointment or shampoo)
• anthralin cream or ointment
• vitamin-D-like cream or ointment (calcipotriene).

Using a steroid for a long time can have serious side effects. Take steroid medicine exactly as your healthcare provider prescribes. Don’t take more or less of it than prescribed by your provider and don’t take it longer than prescribed. Don’t stop taking a steroid without your provider's approval. You may have to lower your dosage slowly before stopping it.

A group of medicines called retinoids have been used to treat severe psoriasis.

• Tazarotene is a very potent gel used on the skin. This medicine may cause birth defects if it is used just before or during pregnancy.
• Acitretin is an oral medicine also called Soriatane. It is much more likely to cause birth defects. It should not be used less than 3 years before pregnancy.

More severe psoriasis may require medicines to suppress your body's immune response. Examples of such medicines are methotrexate and cyclosporine, which are usually taken by mouth. Another example is a medicine called Amevive (alefacept). It prevents your immune system from overreacting and so helps stop the buildup of extra skin cells. It is given as a shot once a week for 12 weeks. You will need some monitoring with blood tests while you are using these medicines.

Your healthcare provider may want you to use more than one type of medicine. If you are using a combination of psoriasis medicines, it is helpful to keep a record of when you use each medicine and review it with your provider at your checkups.

Your healthcare provider may prescribe ultraviolet (UV) light therapy in addition to your medicines. New ways of using ultraviolet light to treat psoriasis include the use of lasers. At least 2 different types of lasers may be used.

• One type of laser emits a form of UV light in a very narrow beam. It usually takes 2 treatments a week for several weeks to improve or clear the plaque. The results may last for several months. You may get a mild sunburn from these treatments.
• The other type of laser is a pulsed dye laser. It uses a different kind of light than other psoriasis light treatments. It destroys the blood vessels beneath the psoriasis plaques and makes it less likely the plaques will return. Treatments are done in 15 to 30-minute sessions, usually about every 3 weeks. This laser can create a stinging feeling during the treatment. It takes several sessions to clear the plaque.

How long will the effects last?

Psoriasis is a chronic disease, which means you will likely have it all of your life. The extent and severity of the disease vary widely. Early treatment of the plaques may help stop the problem from becoming more severe.

How can I help take care of myself?

To help reduce flare-ups:

• Try to avoid skin injuries. Plaques may develop in places where your skin has been injured. When you do hurt your skin, protect it from infection.
• Talk to your healthcare provider about getting the right amount of sun exposure for your skin.
• Avoid stress.
• Exercise daily according to your healthcare provider's recommendation and maintain a healthy weight.
• Avoid drinking too much alcohol.
• Follow your provider's recommendations for keeping your skin soft. Ask your provider to suggest soaps, lotions, and cosmetics.

How can I help prevent psoriasis?

Because the cause of psoriasis is not known, it is not yet possible to prevent it. However, you may be able to prevent serious outbreaks by treating small plaques when you first see them. Follow your healthcare provider's instructions for treatment.

For more information, contact:

• The National Psoriasis Foundation
  Phone: 800-723-9166
  Web site: http://www.psoriasis.org

  The Foundation provides educational materials, referrals to specialists, and staff to answer questions.