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.
How does it occur?
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 psoriasis 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 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 primary care provider will examine your skin and nails. For more information or to confirm the diagnosis, your primary care 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 primary care 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 primary care provider prescribes. Don’t take more or less of it than prescribed by your primary care provider and don’t take it longer than prescribed. Don’t stop taking a steroid without your primary care 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 cyclosporin, which are usually taken by mouth.
Your primary care 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 primary care provider at your checkups.
Your primary care 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 plaque 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.
Effective New Treatments
Two newer prescription treatments are available in Canada.
Dovobet (calcipotriol/betamethasone diproprionate) is a new product that combines the two gold standard medicines, corticosteroid and the vitamin D derivative calcipotriol. This medication is appropriate for patients with mild to moderate disease.
It is applied once a day at bedtime. It is a topical treatment that is steroid-sparing and works quickly to reduce the signs and symptoms of psoriasis, usually providing noticeable results within one to four weeks. Dovobet is cost effective because less medicine is used in order to resolve a flare.
Tazorac (tazarotene) a new cream formulation of a retinoid made from Vitamin A, can be used with emollient creams, once daily in the evening. These with mild to moderate psoriasis who have had success with the gel product may be interested in the new cream since it is generally better tolerated. Cost for the new cream formulation of Tazorac is comparable to that of the gel product.
Research is ongoing to develop ‘biologic therapies’ for psoriasis including new treatments known as immunomodulators which block the disease pathways. Of the products in development, two are expected to be available in Canada in the next year or so. These agents will be most helpful to people with widespread disease or with systemic complications such as psoriatic arthritis.
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 primary care provider about getting the right amount of sun exposure for your skin
· Avoid stress.
· Exercise daily according to your primary care provider’s recommendation and maintain a healthy weight.
· Avoid drinking too much alcohol.
· Follow your primary care provider’s recommendations for keeping your skin soft. Ask your primary care 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 primary care provider’s instructions for treatment.
Where can I get more information?
For more information on psoriasis contact:
The Canadian Dermatology Association
Web site: www.dermatology.ca