Normally, skin cells are constantly being formed, then pushed up to the surface where they eventually die and flake off, revealing new skin cells. In people with psoriasis, however, the skin cells grow too quickly, causing layers of skin to build up, forming a whitish, flaky crust. Blood vessels increase flow in an attempt to nourish this skin, causing reddened inflammation. Thus the hallmark symptoms of psoriasis are reddened, inflamed skin with a whitish, flaky layer of dead cells on top.
Although psoriasis usually appears as a skin condition, recent discoveries show that its real cause is a problem with the immune system.
Your body naturally fights infections and heals injuries with special cells -- called white blood cells -- that are designed to battle viruses or bacteria. Normally these cells go to the site of infection or injury and release antibodies and other chemicals to repair wounds, clot blood and prevent infection. One byproduct of this normal process is inflammation (redness and swelling).
For reasons that doctors don't yet understand, the immune systems of people with psoriasis malfunction. One type of white blood cell - the B-cell - begins creating antibodies that destroy normal skin cells. Another type of white blood cell - the T-cell - begins overproducing a substance called cytokines. This overproduction turns off a signal that regulates skin cell grow.
That's why psoriasis is considered an autoimmune disease - the immune system malfunctions and turns on normal body tissues. Other autoimmune diseases include lupus and rheumatoid arthritis.
Psoriasis of the skin or nails may look like a rash or fungus, but you can't catch psoriasis from another person and you can't give it to anyone else. You also can't spread it from one part of your body to another by touch. Experts now know that a susceptibility to getting psoriasis can be inherited. If it runs in your family, your chances of developing psoriasis are higher.
