Psoriasis is one of mankind's most common skin conditions. Approximately 2 percent of the US population has psoriasis.(1) Equally common in men and women, psoriasis affects all age groups.(2, 3)

Psoriasis looks like a red skin rash loosely covered with silvery white scales. It often appears on the elbows, knees, scalp, or low back. For reasons not completely understood, skin cells in these areas reproduce too rapidly and build up faster than they can be sloughed off.(4) These excess skin cells form the characteristic scaly rash. A number of causes are theorized, including genetics and external triggers such as climate, infection, injury, and drugs. Psoriasis seems to involve two underlying mechanisms: a defect in the reproductive cycle of skin cells and high levels of a fatty acid normally present in cells called "arachidonic acid". Weather is a factor: warm seasons and sunlight improve psoriasis in 80 percent of people with the disease, while 90 percent report worsening in cold weather. Stress seems to play a role in psoriasis, as 30 to 40 percent of sufferers report flare ups during times of stress.

Psoriasis is usually manageable, and it often goes into remission. Avoiding stress, following good dietary habits and keeping weight down can help control psoriasis.

Psoriasis is sometimes associated with a serious joint disease arthritis called “psoriatic arthritis.” Along with the typical psoriasis skin rash, joints in the hands, knees, wrists, elbows, and ankles become severely inflamed.