Psoriasis

A chronic inflammatory disease of the skin.  Symptoms may include red plaques (raised plateaulike lesions) with silvery white scales on the scalp, trunk, and limbs.  Other types may include pustular (small pus blisters on a red base) and erythrodermic (redness on most of the body caused by inflammation).  The nails may also be affected, with discoloration, small pits, and lifting of the nail plate.  Treatment includes topical corticosteroids or other medications, phototherapy (exposure to ultraviolet light), oral vitamin A (retinoids), chemotherapy, or immunosuppressive drugs.