OBJECTIVES: To characterize generalized pustular psoriasis (GPP) and describe treatments, and healthcare resource utilization (HCRU) associated with GPP flares in Canada.

METHODS: This was a retrospective, observational cohort study based on data extracted from medical charts of patients diagnosed with GPP between January 2011 and December 2020 at participating dermatology centers in Canada. Patients were followed from diagnosis date until the earliest of June 2021 or death.

RESULTS: Fifteen patients from four centers in Quebec, Ontario and Alberta were included (mean age 60.3 years, 77.3% female). Sixty percent of patients had concomitant plaque psoriasis and 20% had depression and/or anxiety. Eight (53.3%) patients had public healthcare insurance. During follow-up, one (6.7%) patient died while 66.7% of patients had at least one flare, resulting in a rate of 0.5 (IQR: 0.3-0.9) flares per person-year. Nine (60%) patients had at least one emergency department visit or hospitalization related to GPP. Among these patients, the median cumulative length of stay per person-year was 5.8 days (3.4-26.0). Two (13.3%) patients had a record of receiving sickness or disability benefits. Overall, 73.3% of patients received topical corticosteroids for the treatment of GPP flare, 46.7% received oral corticosteroids and 13.3% received a biologic. The majority of treatments administered for GPP flares resulted in no or partial response.

CONCLUSIONS: GPP is a rare disease and patients in Canada face considerable disease burden with high HCRU associated with flares. The absence of approved medications for GPP flares at the time of the study or a consensus in clinical guidelines for the management of GPP may account for the varied treatments that are given off-label to patients. As reported in our study, treatments currently administered for GPP flares are often ineffective, highlighting the high unmet need for new treatments for patients with GPP.