Evaluation of a Case Series of Patients with Generalized Pustular Psoriasis in the United States

Importance: Generalized pustular psoriasis (GPP) is a chronic, orphan disease with limited epidemiological data. Objective: To describe the clinical characteristics, treatments, longitudinal disease course, and disease-specific health care utilization among patients with GPP across the United States. Design, Setting, and Participants: A retrospective longitudinal case series involving 95 adults who met the European Rare and Severe Psoriasis Expert Network consensus definition for GPP and were treated at 20 US academic dermatology practices between January 1, 2007, and December 31, 2018. Main Outcomes and Measures: The primary outcome is to describe the patient characteristics, associated medical comorbidities, treatment patterns complications, and GPP-specific health care utilization. Results: Sixty-seven of 95 patients (70.5%) were women (mean age, 50.3 years [SD, 16.1 years]). In the initial encounter, 35 patients (36.8%) were hospitalized and 64 (67.4%) were treated with systemic therapies. In total, more than 20 different systemic therapies were tried. During the follow-up period, 19 patients (35.8%) reported hospitalizations at a median rate of 0.5 hospitalizations per year (IQR, 0.4-1.6). Women had a decreased risk of an emergency department or hospital encounter (odds ratio, 0.19; 95% CI, 0.04-0.83). Conclusions and Relevance: Generalized pustular psoriasis is a rare, chronic disease without standard treatment and is associated with continued health care utilization over time.