OBJECTIVES: To document the incidence and economic burden associated with palmoplantar pustolosis (PPP) management in Canadian hospitals, emergency departments (ED) and hospital-/community-based outpatient clinics, and to compare with plaque psoriasis (PP).

METHODS: Data from the Canadian Institute for Health Information were used to identify adult Canadians (excluding Quebec) hospitalized or visiting an ED or hospital-/community-based outpatient clinic with a most responsible diagnosis (MRD) code indicating PPP (i.e., ICD-10-CA L40.3) or PP (ICD10-CA L40.9 or L40.0). Incident cases were defined as having a PPP/PP MRD code for the 5 fiscal years (April 1, 2012 to March 31, 2017) without any PPP/PP MRD code in the 5 previous years (April 1, 2007 to March 31, 2012) allowing every case to have 3-year follow-up data (up to March 31, 2020). Patient characteristics and 3-year MRD costs were documented. Generalized linear models (gamma distribution; log link) were conducted for comparing the 3-year costs between PPP and PP. Sensitivity analyses were conducted considering all inpatient resource use independent of the presence of a PPP/PP diagnostic code in the administrative records (i.e., all-cause costs).

RESULTS: Over the 5-year time period, 101 incident cases of PP (5-year incidence rate: 0.93/1,000,000) and 5,979 incident cases of PP (5-year incidence rate: 54.93/1,000,000) were identified. There was no difference between PPP and PP patients in terms of mean age (standard deviation) (49.8 [17.8] years versus 48.3 [17.8] years; p=0.39) or sex (52.5% female versus 45.3% female; p=0.15). Over the 3-year period following the incident index date, MRD mean (SD) costs were $1,078 ($2,705) for PPP and $503 ($2,267) for PP (p<0.01). Three-year all-cause mean (SD) costs associated with any healthcare resource utilization were $6,341 ($10,041) for PPP and $10,109 ($30,212) for PP (p<0.01).

CONCLUSIONS: The burden of PPP is significant. PPP patients incurred significantly higher MRD costs than PP patients.