Psoriasis is a chronic, non-infectious, immune-mediated inflammatory skin disorder, characterized by well-defined salmon-pink lesions on the scalp, trunk and extensor surfaces that are itchy and scaly. While the cause of psoriasis is still unknown, there is often a genetic predisposition and it is commonly triggered by environmental factors. Multiple medical comorbidities have been linked to psoriasis, such as psoriatic arthritis, metabolic syndrome, diabetes and cardiovascular disease.
Psoriasis can range from mild, moderate to severe disease and affects approximately 3% of the world’s population, or about 125 million people, with onset typically between the ages of 15 to 25 years – although psoriasis can develop at any age. The incidence of psoriasis is dependent on the climate and genetic heritage of the population, with prevalence increasing in colder climates and in those with lighter skin. It is estimated that over 9 million people in the US suffer from psoriasis.