Psoriasis is a common, chronic, autoimmune disease that causes dry, red, scaly patches and flakes to appear on the skin. The rash often goes away for a while, but then it flares up again, often as a result of a trigger, such as stress.It is thought to happen when the immune system mistakenly starts producing skin cells too quickly.Psoriasis affects around 3 percent of people globally, and around 7.5 million people in the United States (U.S.).It affects men and women equally. It can begin at any age, but it is most common between the ages of 15 and 35 years, and again between 50 and 60 years. The average age is 28 years.Around 15 percent of cases emerge before the age of 10 years.M r nd more, people are turn ng to CBD l for r l f, rt ul rl wh n r r t n medicines f l, and f l they d .Th r r f v t f r , all presenting slightly d ff r nt m t m . Pl u r , or r vulg r , th m t common, presenting n n rl 80 r nt of cases.It h w on h nd , nails, l , nd th r xtr m t , u h as kn and elbows.