What genetic disease involves the buildup of a thick, reddish skin tissue that is covered with silvery scales, and often appears first on the elbows and knees?

Psoriasis occurs when the immune system overreacts with the skin. It causes faster than normal regeneration of skin cells which leads to a buildup. It can be triggered by stress, scratching the skin, cold weather or other infections. It is not contagious and is a local contraindication.