(302) Canadian Pustular Psoriasis Study (CAPPS): Examining disease burden, treatments and healthcare resource utilization for palmoplantar pustulosis in Canada

Background: Palmoplantar pustulosis (PPP) is a form of chronic, localized pustular psoriasis characterized by the development of sterile pustules on the palms and soles. The clinical burden, health resource utilization and treatment patterns among PPP patients in Canada is not well described.

Objectives: To characterize the clinical burden, management and treatment patterns of patients with PPP in Canada.

Methods: This was a retrospective, observational cohort study based on data extracted from medical charts of patients diagnosed with PPP between 1st January 2011 and 31st December 2020 at participating dermatology centers across Canada. Patients were followed from diagnosis date until the earliest of 1st June 2021, date of last visit, or date of death. Data relating to patient demographic and clinical characteristics, PPP-related healthcare resource utilization and treatments were summarized using descriptive statistics.

Results: Forty-one patients from four centers in Alberta, Ontario and Quebec were included (mean age: 54 years, 78.0% female, 46.3% current smokers, 31.7% history of plaque psoriasis). The most common cutaneous symptoms at PPP diagnosis were scaling (81.6%), pustules (82.5%), erythema (68.4%) and pain (40.5%). During a median (interquartile range) follow-up time of 2.5 (0.8-5.5) years, there were 163 recorded physician visits, 4 emergency department visits and 4 hospitalizations, including 1 hospitalization involving an intensive care unit admission. The majority of patients received topical treatments (N=33, 80.5%) during follow-up, including 22 (53.7%) patients who received clobetasol and 16 (53.7%) who received betamethasone. There were 21 (51.2%) patients who received non-biologic systemic treatments, including 15 (36.6%) who received retinoids and 9 (22.0%) who received methotrexate. Eleven (26.8%) patients received a biologic treatment during follow-up, including 8 (19.5%) patients who received an anti-interleukin-17 agent. Most treatments resulted in no or partial response. There were no treatments which led to a complete response for all patients, though 4 of 6 treatment episodes using narrow-band ultraviolet-B light resulted in a complete response.

Conclusions: PPP is a condition associated with considerable symptom burden. There was considerable heterogeneity in the medications administered for the treatment of PPP in Canada, yet many of these drugs did not result in a complete response. The identification of safe and effective treatments for this condition remains a key unmet need.