This chronic disease affects people of all ages and appears to be inherited . Over 125 million people worldwide suffer from psoriasis.

This disease causes skin redness and irritation that occurs anywhere in the body. Most people with psoriasis have thick , red skin with flaky patches , silvery white . There is no known way to prevent psoriasis and is not contagious .

Psoriasis is the most common autoimmune disease . Researchers think it probably occurs when the immune system attacks healthy cells, to confuse them with hazardous substances. Up to a third of people with psoriasis may also develop a form of arthritis known as " psoriatic arthritis , " in which the immune system also attacks the joints .

Factors that may trigger psoriasis include stress , dry air , infections, skin lesions , some drugs, too much or too little sun , cold weather, excessive alcohol consumption and smoking.

There are three basic methods for the treatment of psoriasis : topical medications , internal medicine and phototherapy .

Most cases of psoriasis are treated with medications that are applied directly to the skin . These include creams and ointments , shampoos, moisturizers and medicines containing vitamin D or vitamin A.

Severe psoriasis can be treated with drugs that suppress the body's immune response . These drugs include methotrexate or cyclosporine . Also, new drugs called "biologics " are used to target specifically the immune system. These include: Adalimumab , etanercept and infliximab .

Light therapy is also used as treatment and involves careful skin exposure to ultraviolet light .

Home remedies include oatmeal baths to soothe and loosen the scales , moderate sun exposure, and relaxation techniques like meditation to relieve stress.

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