Skin lesions, or plaques due to psoriasis most often develop on the scalp, knees, elbows, lower back and feet. They are generally itchy and painful, and can crack and bleed. The size of plaques may vary. They appear as distinct patches or as joined together covering a large surface of your skin.
When the underlying cells reach the skin's surface and die, their volume causes sumptoms to develop in the form of raised, red plaques covered with white scales. Psoriasis generally affects your knees, elbows, and scalp, but it can also affect the torso, palms, and the feet.