Risk of suicidal ideation and suicide attempt in patients with prurigo nodularis

Background: Prurigo nodularis (PN) is a chronic, inflammatory skin disorder characterized by unrelenting itch and multiple pruriginous lesions. PN is associated with a severe burden of disease and mental health comorbidities. The risk of suicidality among patients with PN is unknown. We performed a multicenter, longitudinal cohort study using TriNetX, a health research network that provides access to electronic medical record data. We identified patients with PN using a validated ICD-10-CM code and compared to patients without PN. We performed 1:1 propensity-score matching for PN patients and controls, based on age, sex, race/ethnicity, and potential confounders. We estimated the 1-year incidence of suicidal ideation (SI) and suicide attempt., also identified via ICD-10-CM codes. We further performed Cox proportional-hazards models to estimate the risk of SI and suicide attempt. There were 20,093 patients in the PN and control groups and no significant differences were observed following matching. The incidence of SI was increased significantly in PN patients (1.17%) compared to controls (0.44%) [P <0.0001]. Similarly, attempted suicide within one year was more common in PN patients (0.23% vs. 0.13%; P <0.0001). Cox proportional-hazards regression revealed a significantly elevated risk of SI (HR = 2.50; 95% CI: 1.95-3.20) and suicide attempt (HR = 1.70; 95% CI: 1.05-2.78) in PN patients. In this multicenter cohort study, we demonstrated increased 1-year incidence and risk of SI and suicide attempt following diagnosis of PN. Dermatologists should be aware of this association, screen and monitor patients, and refer to mental health specialists when appropriate.