The lesions vary in appearance with the type of psoriasis. There are five types of psoriasis: Plaque, guttate, pustular, inverse, and erythrodermic. About 80% of people living with psoriasis have plaque psoriasis, also called “psoriasis vulgaris.” Plaque psoriasis causes patches of thick, scaly skin that may be white, silvery, or red. Called plaques, these patches can develop anywhere on the skin. The most common areas to find plaques are the elbows, knees, lower back, and scalp.