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Psoriasis (suh-REYE-uh-suhss) is a long-lasting skin disease. In the most common form of psoriasis, thick red patches covered with silvery scales usually appear on the head, elbows, and knees. But they can show up on other parts of the body.
Psoriasis is caused by a problem with the body's defense system, called the immune system. In psoriasis, part of the immune system is overactive, causing skin cells that grow deep in the skin to rise to the surface much faster than normal. So, skin cells build up in the affected area, and thick patches result.
The itching and pain of psoriasis can interfere with daily activities, such as walking, sleeping, and taking care of yourself. Plaques on the hands and feet can prevent you from working at certain jobs, playing some sports, and caring for family members. Psoriasis can also make you feel self-conscious about your appearance and afraid of being rejected by others. These concerns can lead to social isolation and depression.
If you have psoriasis, you may notice that there are times when your skin worsens, then improves. Things that can cause your skin to get worse include:
- Weather changes that dry the skin
- Certain medicines
Anyone can get psoriasis. But it occurs more often in adults. Sometimes psoriasis runs in families. Certain genes have been linked to the disease.
Psoriasis can be hard to diagnose because it can look like other skin diseases. The doctor might need to look at a small skin sample under a microscope. The good news is that psoriasis can be treated. Therapies include:
- Light treatment
Explore other publications and websites
About Psoriasis (Copyright © National Psoriasis Foundation) — This fact sheet gives information on psoriasis, including the causes, symptoms, and treatment options. This publication also links to information that explains the different types of psoriasis in detail.
Minimizing Flare-Ups (Copyright © American Academy of Dermatology) — By performing certain everyday habits (and abstaining from some others), you can greatly reduce the effect of psoriasis on your life. This site explains how you can take control and limit psoriasis flare-ups.
Psoriasis Triggers (Copyright © American Academy of Dermatology) — This site explains how certain triggers can cause psoriasis symptoms to flare up from time to time, and describes what those triggers could be.
PsoriasisNet (Copyright © American Academy of Dermatology) — This site includes comprehensive information about psoriasis, such as what it is, what causes it, and what treatment options are available.
Psoriatic Arthritis (Copyright © American College of Rheumatology) — This fact sheet provides information on psoriatic arthritis, a chronic skin and nail disease associated with inflammatory arthritis. It explains the causes, diagnosis, treatments, and why a rheumatologist might be needed to make a correct diagnosis of the disease.
Psoriatic Arthritis (Copyright © Arthritis Foundation) — This fact sheet provides information on psoriatic arthritis including the symptoms, causes, diagnosis, and treatment options, as well as who is at risk.
Questions and Answers About Psoriasis — This booklet provides general information about psoriasis. It describes what psoriasis is, what causes it, and how it is treated. It also includes a list of resources.
Treating Psoriasis (Copyright © National Psoriasis Foundation) — This online publication discusses the treatment options available for psoriasis.
Treating Psoriatic Arthritis (Copyright © National Psoriasis Foundation) — This online publication discusses the treatment options available for psoriatic arthritis.
Connect with other organizations
American Academy of Dermatology
National Psoriasis Foundation
Content last updated September 22, 2009.
Resources last updated September 22, 2009.
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