Prurigo nodularis (IMAGE) Johns Hopkins Medicine Caption Prurigo nodularis (PN) is a chronic skin disease that affects an estimated 72 out of 100,000 people in the U.S. Johns Hopkins reserachers found two distinct clusters of patients: noninflammatory plasma profiles, in which patients had a greater likelihood of spinal disease (Cluster 1), and inflammatory plasma profiles (Cluster 2). Credit Shawn Kwatra Usage Restrictions none License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.