Psoriasis is a skin disease that causes scaling and inflammation. Skin cells grow deep in the skin and slowly rise to the surface, a process called cell turnover that takes about a month. For psoriasis the process takes a few days as the cells rise too fast and pile up on the surface. Usually found on the elbows, knees, scalp, lower back, face, palms and soles of the feet. But can be on fingernails, toenails, genitals and inside the mouth. Severe cases involve large parts of the skin and are treated by a skin specialist.
Attribution: Straight Talk Foundation