This is the most common of the five main psoriasis types. As many as 9 out of 10 people with the condition have plaque psoriasis, which is often mild. Patches can appear on your elbows, knees, lower back, scalp, and palms and soles of feet. You may have dry, raised red lesions (plaques) that are capped with a scaly, silvery buildup of dead skin. Plaque psoriasis can strike anywhere, including on your penis, around your genitals, and inside your mouth.