Psoriasis

Overview

Once described simply as a skin condition research has shown that psoriasis is actually a disease of the immune system that causes abnormally rapid growth in skin cells.

Between one and three percent of the population has psoriasis. It affects men and women equally. It can occur at any age but the onset is usually gradual and the diagnosis is commonly made between the ages of 15 and 35.

Causes

The "epidermis" or outer layer of the skin is constantly manufacturing new cells and shedding old ones. This usually takes about 28 days and is unnoticeable. In psoriasis it all happens much faster generally within 4 or 5 days. Because it is so rapid outer cells remain on the skin appearing as red inflamed areas covered by silvery scales. Psoriasis might be confined to small areas of the skin such as the knees elbows or hair or it may appear over large parts of the body.

While scientists still do not know exactly what causes psoriasis there is overwhelming evidence that it is an inherited condition that is influenced by other factors. The immune system is believed to play a critical role in setting in motion a chain of events that results in psoriasis.

There is no link between hygiene and psoriasis. Psoriasis is a disease of the immune system and no amount of washing or scrubbing can remove the scaly areas or ensure they don't come back.

Symptoms

There are five different types of psoriasis. The most common form is "plaque psoriasis" which is characterized by well-defined patches of red raised skin. About 80 percent of people with psoriasis have this type. Plaque psoriasis can appear on any skin surface although the knees elbows scalp trunk and nails are the most common locations.

The other types of psoriasis are:
  • Guttate: small red individual drops on the skin
  • Inverse: smooth dry areas of skin often in folds or creases that are red and inflamed but do not have scaling
  • Erythrodermic: periodic widespread fiery redness of the skin
  • Pustular: involves either generalized widespread areas of reddened skin or localized areas particularly the hands and feet

Typically people have only one form of psoriasis at a time. Sometimes two different types can occur together one type may change to another type or one type may become more severe. There are certain "triggers" that can set this process into motion including emotional stress injury to the skin sunburns certain infections and reaction to some drugs.

The different types of psoriasis not only have different appearances but also may require different types of treatment. It is very important that you talk with your doctor about what course of action to take with your particular type of psoriasis.

Once symptoms appear patients have psoriasis for life. There is currently no cure. The condition goes through cycles usually flaring up for weeks or months and then subsiding before coming back again. Psoriasis is often highly visible. As a result in addition to the physical burden that comes with the disease there can be an emotional or psychological impact. Many people with psoriasis have feelings of helplessness hopelessness anger frustration and even depression related to the appearance of their skin and how others react to their condition.

Psoriasis is not contagious. You can't catch the disease from another person and you can't pass it on to someone else by touching or having close contact with them.

Treatment

Because there is currently no cure for psoriasis existing treatments are aimed at controlling or temporarily eliminating the symptoms of the disease. Treatments range from topical therapies (applied to the skin) for mild psoriasis to light therapy and systemic therapy (medications taken by tablet or injection) for more severe cases.

In general the course of psoriasis is unpredictable and irregular. Nevertheless under treatment the plaques will frequently disappear entirely or the disease will retreat to a few spots on elbows or knees. These minimal spots or some slight pitting on the nails may remain minimal for years. Then under severe stress or for some other unknown reason the rash may again flare up. This erratic course may go on for years often with long periods of freedom from skin trouble.

These steps may help improve symptoms of psoriasis:

  • Never scratch rub or pick at patches of psoriasis
  • Soak off the scales by bathing daily.
  • Use soaps shampoos cleansers or ointments containing coal tar or salicylic acid but never alcohol.
  • Keep your skin moist. Use cortisone creams when symptoms are especially bad.
  • Use a humidifier and keep room temperatures cool
  • Eat a balanced diet
  • Exercise regularly
  • Get adequate sleep
  • Avoid sunburn. Expose your skin only to moderate sunlight

Complications

At least 10 percent of people with psoriasis also develop psoriatic arthritis which generally produces some pain and discomfort in affected joints but has little effect on general health.

Additional Resources

Psoriasis Society of Canada

Psoriasis Education Program