Jane Brody, an award-winning health reporter at the New York Times, wrote a fine column on Psoriasis (July 5, 2011).
Ms. Brody tells us "Psoriasis is one of the most common skin ailments, affecting about 2 percent of the population, with no respect for gender, age or socioeconomic status. Caucasians. As with other genetically influenced diseases, psoriasis tends to run in families. If both parents have it, their children have about a 40 percent chance of also developing it; the risk drops to 14 percent if only one parent is affected."
Click on For Many Millions, Psoriasis Means Misery to access the full article.