Psoriasis

Psoriasis is a common, genetically determined, inflammatory skin disorder of unknown cause, which, in its most usual form, is characterized by well demarcated, raised, red scaling patches that preferentially localize to the extensor surfaces.

Typical lesions are red, raised, scaly, and have well demarcated margins. The scaling is often slivery or thick like candle grease. Plagues vary enormously in shape and size. They often start out discoid, but ends up polycyclic