Johns Hopkins researchers report that prurigo nodularis (PN), a skin disease characterized by severely itchy, firm bumps on the skin, may be associated with other inflammatory skin disorders as well as systemic and mental health disorders. Compared with other skin diseases, however, not much is known about PN. While symptoms of PN can be managed, no cures exist. Researchers were looking to determine associated conditions that are more common in patients with PN, compared with similar patients without PN.