[header] How to diagnose psoriasis [title] Look for red patches of skin that appear scaly. [step] You should look for any red patches of skin on your body, including your genitals and the inside of your mouth. The red patches may look like they are covered with silvery scales and may only appear in a few spots on your body or in large areas on your body. 
If you notice these symptoms, you may have a type of psoriasis called plaque psoriasis. This is the most common form of psoriasis.