Psoriasis is an incurable, non-contagious skin disease. It is a chronic illness, which hyperproliferates on the skin. Its cause is unknown, and it varies greatly in the severity and distribution of the cutaneous lesions (normally on the knees and elbows, the scalp and lumbar region). - 190 million is the number of the world population that suffers from psoriasis; - In Europe the number of people that suffer from psoriasis is between 1.5% and 4.5% of the total population; - 20-40 is the age range where psoriasis manifests most frequently, although it can arise at any stage of life; - 30% of people that have psoriasis present a related family history.