Psoriasis
Topic Overview
What is psoriasis?
Psoriasis (say "suh-RY-uh-sus") is a long-term (chronic) skin problem that causes skin cells to grow too quickly, resulting in thick, white, silvery, or red patches of skin. Normally, skin cells grow gradually and flake off about every 4 weeks. New skin cells grow to replace the outer layers of the skin as they shed. But in psoriasis, new skin cells move rapidly to the surface of the skin in days rather than weeks. They build up and form thick patches called plaques (say "plax").
The patches range in size from small to large. They most often appear on the knees, elbows, scalp, hands, feet, or lower back. Psoriasis is most common in adults, but children and teens can get it too.
Having psoriasis can be embarrassing, and many people, especially teens, avoid swimming and other situations where patches can show. But there are many types of treatment that can help keep psoriasis under control.
See a picture of psoriasis
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What causes psoriasis?
Experts believe that psoriasis occurs when the immune system overreacts, causing inflammation and flaking of skin.
In some cases, psoriasis runs in families. Researchers are studying large families affected by psoriasis to find out how it is passed from parents to their children and what might trigger the condition.
People with psoriasis often notice times when their skin gets worse. Things that can cause these flare-ups include a cold and dry climate, infections, stress, and dry skin. Also, certain medicines, such as non-steroidal anti-inflammatory drugs (NSAIDs) and medicines used to treat high blood pressure or certain mental illnesses, may trigger an outbreak or make your psoriasis worse.
Smoking, especially in women, makes you more likely to get psoriasis and can make it worse if you already have it.
Psoriasis is not contagious. It cannot be spread by touch from person to person.
What are the symptoms?
Symptoms of psoriasis appear in different ways. Psoriasis can be mild, with small areas of rash. When psoriasis is moderate or severe, the skin gets inflamed with raised red areas topped with loose, silvery, scaling skin. If psoriasis is severe, the skin becomes itchy and tender, and the large skin patches may be uncomfortable and embarrassing. The patches can join together and cover large areas of skin, such as the entire back.
In some people, psoriasis causes joints to become swollen, tender, and painful. This is called psoriatic arthritis (say "sor-ee-AT-ik ar-THRY-tus"). This arthritis can also affect the fingernails and toenails, causing the nails to pit, change colour, and separate from the nail bed. Dead skin may build up under the nails.
Symptoms often disappear (go into remission), even without treatment, and then return (flare up).
How is psoriasis diagnosed?
A doctor can usually diagnose psoriasis by looking at the patches on your skin, scalp, or nails. Sometimes a skin KOH test is used to rule out a fungal infection, but otherwise, special tests are usually not needed.
How is it treated?
Most cases of psoriasis are mild, and treatment begins with skin care. This includes keeping your skin moist with creams and lotions. These are often used with other treatments including shampoos, ultraviolet light, and medicines your doctor prescribes.
In some cases, psoriasis can be hard to treat. You may need to try different combinations of treatments to find what works for you. Treatment for psoriasis may continue for a lifetime.
What can you do at home for psoriasis?
Skin care at home can help control psoriasis. Follow these tips to care for psoriasis:
- Use creams or lotions, baths, or soaks to keep your skin moist.
- Try short exposure to sunlight or ultraviolet (UV) light.
- Gently soften and remove psoriasis crusts by putting cream on the crusts and then peeling the loose crusts off. Removing crusts may help your skin to absorb creams and lotions. Remove them carefully, though, so you don't irritate the skin.
- Follow instructions for skin products and prescribed medicines. It may take a period of trial and error until you know which skin products or procedures work best for you. For mild symptoms of psoriasis, some over-the-counter medicines, such as aloe vera, may be soothing.
It is also important to avoid those things that can cause psoriasis symptoms to flare up or make the condition worse. Things to avoid include:
- Skin injury. An injury to the skin can cause psoriasis patches to form anywhere on the body, including the site of the injury. This includes injuries to your nails or nearby skin while trimming your nails.
- Stress and anxiety. Stress can cause psoriasis to appear suddenly (flare) or can make symptoms worse.
- Infection. Infections such as strep throat can cause psoriasis to appear suddenly, especially in children.
- Certain medicines. Some medicines, such as NSAIDs, beta-blockers, and lithium, have been found to make psoriasis symptoms worse. Talk with your doctor. You may be able to take a different medicine.
- Overexposure to sunlight. Although short periods of sun exposure reduce psoriasis in most people, too much sun can damage the skin and cause skin cancer. And sunburns can trigger flares of psoriasis.
- Alcohol. Alcohol use can cause symptoms to flare up.
- Smoking. If you smoke, try to quit. Smoking, especially in women, makes you more likely to get psoriasis and can make it worse if you already have it.
Studies have not found that specific diets can cure or improve the condition, although some advertisements claim to. For some people, not eating certain foods helps their psoriasis. Most doctors recommend that you eat a balanced diet to be healthy and stay at a healthy weight.
Frequently Asked Questions
Learning about psoriasis:
Being diagnosed:
Getting treatment:
Ongoing concerns:
Living with psoriasis:
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| Author: | Douglas Dana Maria G. Essig, MS, ELS | Last Updated: February 15, 2008 |
| Medical Review: | Anne C. Poinier, MD - Internal Medicine Kathleen Romito, MD - Family Medicine Alexander H. Murray, MD, FRCPC - Dermatology | |
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