Prurigo Nodularis (PN) is a skin disease that causes hard, itchy lumps (nodules) to form on the skin. The itching can be intense, causing people to scratch themselves to the point of bleeding or pain. Scratching can cause more skin lesions to appear. Although scratching is known to cause more nodules to appear, it is unclear what causes the itching to develop in the first place. We are seeking qualified participants from the Houston area who have severe itching related to Prurigo Nodularis.