Living With Psoriasis

By Jack Toole, MD

Psoriasis is a difficult to treat (chronic relapsing) disease that affects the skin and occasionally the joints.

About 2 % of the population will have the disease.

What Causes Psoriasis?

To develop psoriasis you must carry a specific type of genetic material and experience a “trigger” condition. For example it is known that a bacterial infection, an injury or certain medications can stimulate psoriasis.

We have learned in the past decade that the rash we see in psoriasis is a result of a disorder in the immune system. The immune system normally attacks cancers and infections attempting to invade the body. In psoriasis certain immune system cells, referred to as T cells, become over activated - and this results in changes in the skin and joints.

You can have psoriasis at any age. It usually begins with scaly red patches appearing on the scalp, knees and elbows. The diagnosis is usually straightforward, however cutting out a small piece of skin and examining it under the microscope (a biopsy) can be helpful in difficult cases.

Is There A Cure?

Currently there is no cure for psoriasis. There are however an expanding range of effective treatments.

How Can I Cope With My Psoriasis?

Management of psoriasis begins with common sense. Here are some tips that will help to control disease:

• Promptly treat any skin infection
• Avoid unnecessary injury to the skin
• If possible, avoid certain prescription drugs which may aggravate your psoriasis

How Do I Deal With The Rash?

There are a large number compounds which diminish or eliminate the rash. Cortisone based creams are effective and easy to use but after prolonged use they become less effective and can cause thinning of the skin. Tar based preparations also are effective and safe in treating psoriasis - however many of these have a foul odour and can stain clothing.

Cacipotriol is a vitamin D like molecule that is effective when applied to psoriasis . It is convenient and safe for treating limited psoriasis.

Other Treatments:

Patients whose psoriasis covers more than 10% of their bodies often find application of creams too time consuming and expensive. There are some alternative methods of treatment available:

• Ultraviolet B light therapy offers an effective method of treating more extensive psoriasis. This requires access to a treatment center that can supply this treatment. There are concerns about excessive exposure to ultraviolet light and hence increase risk of skin cancer, yet this treatment has proven to be safe and effective.
• PUVA is another form of therapy in which Ultraviolet A light is directed to the skin after the patient has either applied compounds called Psoralens or ingested them. While very effective it does have a risk of skin cancer after prolonged exposure.
• More severe and resistant cases of psoriasis may require treatment with drugs taken either by mouth or injection These treatments are also safe and effective when used properly but can in some situations produce significant side effects. Cyclosporin can be toxic to the kidneys while Methotrexate may be toxic to the liver and blood. Acetretin is a vitamin A derivative taken by mouth that is also effective. Your Dermatologist will advise you on which course of treatment is best for you.

New Treatments:

The most exciting and dynamic area of therapy in psoriasis involves the use of compounds referred to as biologics . These are molecules specifically designed to correct the steps in the immune system that are abnormal in psoriasis. Although still under development, it is expected these agents will correct the abnormalities in psoriasis while not creating any new problems elsewhere. Biologic therapies include molecules such as alefacept , etanercept and efalizumab are expected to be approved for use in Canada in the near future.