Though the exact cause of psoriasis has yet to be determined, genetic and environmental factors as well as an excessive inflammatory response may play a part. The precise causes of psoriasis are unknown.
Most experts believe that more than one gene is involved.
Researchers have detected at least three genetic regions responsible for inherited conditions. Their role is probably to make affected people more susceptible to certain biochemical, psychological, and environmental factors. When an injury or an infection occurs, white blood cells are mobilized to rid the body of any damaging agents, such as a virus. The masses of blood cells that gather at the injured or infected site cause the area to become inflamed. Normally, when a foreign invader, or antigen, infects the body, helper T-cells recognize the antigen as alien and trigger a series of immune responses to destroy it.