Plaque psoriasis is the most common type of psoriasis, affecting about 80% of people with psoriasis. It appears as patches of raised, reddish skin covered by silvery-white scales. These plaques often form on the elbows, knees, lower back, and scalp but can occur anywhere on the body. Skin can become dry, painful, itchy, and may even bleed or crack, making it hard to sleep or focus on daily activities.