what is psoriasis caused by
Psoriasis causes patches of thick red skin and silvery scales. Patches are typically found on the elbows, knees, scalp, lower back, face, palms, and soles of feet, but can affect other places (fingernails, toenails, and mouth).The most common type of psoriasis is called plaque psoriasis.soriasis causes patches of thick red skin and silvery scales. Patches are typically found on the elbows, knees, scalp, lower back, face, palms, and soles of feet, but can affect other places (fingernails, toenails, and mouth).