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Psoriasis - Cause

The exact cause of psoriasis is not known. Many scientists believe that the condition may be passed down from parents to their children (inherited). About one-third of people who have psoriasis have one or more family members with the condition.1 But it is not clear that genetic factors alone determine whether you develop psoriasis. Psoriasis is not contagious-it cannot be spread by touch from person to person.

Doctors believe that the immune system is a factor in the development of psoriasis. This is because increased numbers of white blood cells are present between the abnormal layers of skin and because psoriasis responds to drugs that suppress the immune system.

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The Signs and Symptoms of Psoriasis

The signs and symptoms of psoriasis vary depending on the type you have. Some common signs for plaque psoriasis -- the most common variety of the condition -- include: Plaques of red, inflamed skin, often covered with loose, silver-colored scales. These plaques may be itchy and painful and sometimes crack and bleed. In severe cases, the plaques will grow and merge into one another, covering large areas. Disorders of the fingernails and toenails, including discoloration and pitting...

Read the The Signs and Symptoms of Psoriasis article > >

Other factors may contribute to the development of psoriasis, make the condition worse, or make it return, including:

  • Climate. Cold, dry weather causes symptoms to become worse. Hot weather, sunlight, and humidity may improve symptoms.
  • 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 (guttate psoriasis), especially in children.
  • Certain medicines. Certain medicines, such as NSAIDs, beta-blockers, and lithium, have been found to make psoriasis symptoms worse. Whenever your doctor prescribes any medicines for you, tell him or her that you have psoriasis.
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WebMD Medical Reference from Healthwise

Last Updated: January 13, 2010
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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