Psoriasis is a common chronic condition which varies in appearance from one person to another. It can come on at any age, and particularly affects the skin of the elbows, knees and scalp. Dull red, scaly raised areas or plaques develop. The scales have a characteristic silvery sheen.
Psoriasis is not usually itchy, but in some people this can become a problem. The fingernails and toenails are frequently affected. Small pits on the surface of the nail may occur. Sometimes the nail thickens or comes off altogether. In the scalp, the skin becomes red. Scales accumulate and make lumps in the scalp.