Treatments and outcomes of generalized pustular psoriasis: A cohort of 1516 patients in a nationwide inpatient database in Japan

Background: Because generalized pustular psoriasis (GPP) is rare, there are few studies reporting treatments and outcomes for large numbers of patients. Objective: To report treatments and outcomes in a large cohort of patients hospitalized with GPP. Methods: Using a Japanese national inpatient database, we identified 1516 patients with GPP who required hospitalization between July 2010 and March 2019. We categorized patients into 3 medication groups: biologics (294 patients), oral agents without biologics (948 patients), and systemic corticosteroids only (274 patients). We investigated their characteristics, treatments, and outcomes. Results: Mean age was 66 years (interquartile range: 52-77 years). Fifty patients (3.3%) were admitted to the intensive care unit, 125 (8.2%) required blood pressure support, and 63 (4.2%) died. Patients who received biologics were younger and had fewer comorbidities. In-hospital mortality was lower in the biologics group (1.0% [biologics group] vs 3.7% [oral-agents group] vs 9.1% [corticosteroids-only group]; P < .001) as was morbidity (5.4% vs 8.2% vs 12%, respectively; P = .02). Among those who received biologics, IL-17 inhibitor use increased over time, with in-hospital mortality and morbidity comparable to those of tumor necrosis factor inhibitors. Limitations: Retrospective study design. Some patients received multiple medications. Conclusion: Biologic treatments showed favorable outcomes compared with other treatments.