Psoriasis is classified by its different signs and symptoms as well as the location of the affected area. Plaque Psoriasis Plaque Psoriasis is the most common form of psoriasis with approximately 90% of psoriasis sufferers having this type.  Plaque psoriasis usually affects the scalp, elbows, knees, lower back, hands, feet and genitals. The face is … Continue reading Types of Psoriasis