Psoriasis affects more than 8 million Americans, according to the <a href="http://www.netreturns.biz/healthinfo/BounceLink.aspx?Shortcut=psoriasis" target="_blank">National Psoriasis Foundation</a>. This skin condition produces red, thickened skin lesions with silvery scales. Lesions usually appear on the scalp, elbows, knees and back.
The lesions result from the overproduction of skin cells. Instead of taking weeks to manufacture skin cells, the body pushes new cells to the surface every few days. Because these cells can't be shed at the rate they're produced, they build up on the skin's surface. 
The redness of psoriatic lesions results from an increased blood supply to the area. The scales are dead skin cells. 
Psoriasis may also cause pitting, loosening or crumbling nails on the fingers and toes. In some cases it causes mild arthritis. 
Psoriasis runs in families. Research suggests that certain triggers cause its first appearance. These may include sunburn, strep throat and certain medications. 
Every case of psoriasis behaves differently. The lesions may disappear spontaneously and reappear years later. The lesions may change in severity and number with every reappearance. Or they may never show up again. 
There is no cure for psoriasis; treatments vary by case. According to the&nbsp;<a href="http://www.netreturns.biz/healthinfo/BounceLink.aspx?Shortcut=niams" target="_blank">National Institute of Arthritis and Musculoskeletal and Skin Diseases</a>, treatments for psoriasis include: 
<ul>
 <li>Topical medicines, like creams.</li>
 <li>Light therapy.</li>
 <li>Pills, liquids or shots.</li>
</ul>
Despite many years of research, the exact cause of psoriasis remains unknown. However, the immune system and genes play important roles, according to the <a href="http://www.netreturns.biz/healthinfo/BounceLink.aspx?Shortcut=aad" target="_blank">American Academy of Dermatology</a>. 
If you think you may have psoriasis, talk to your doctor. 
Reviewed 9/27/2023

Understanding psoriasis

Many treatments can help relieve the symptoms of psoriasis.