OBJECTIVES: Measures of psoriasis (PsO) based on extent of skin manifestations (e.g., body surface area (BSA) and Psoriasis Area and Severity Index [PASI]) are used for therapeutic and reimbursement decisions for systemic therapies. Patients with moderate-severe disease are typically eligible for systemic therapies per label. We sought to understand whether 2020 International Psoriasis Council (IPC) criteria for disease severity and eligibility for systemic therapy would identify patients with low BSA associated with significant disease burden or worse outcomes.

METHODS: Data from the Adelphi Psoriasis Disease Specific Programme, a point-in-time study of physicians and adult PsO patients in the US, France, Germany, Italy, Spain, and the UK between 2018-2019 were queried. Physicians during routine care categorized patients as having mild, moderate, or severe PsO; the latter two were combined into a single moderate-severe category (eligible for systemic therapy per label). Additionally, PsO was retrospectively classified dichotomously based on eligibility for systemic therapy according to IPC criteria of: BSA ≥10%; plaque in sensitive areas; or failed control with topical therapy. Agreement regarding eligibility for systemic therapy between physician assessments and IPC criteria was assessed.

RESULTS: Of 3,866 cases reviewed, agreement between physician assessed and IPC criteria-based eligibility for systemic therapy was limited (55%, kappa: 0.17; p<0.0001). Patients with physician-assessed mild PsO but eligible for systemic therapy (by IPC criteria) had worse outcomes than those with mild PsO who were ineligible for systemic therapy, but better outcomes than severe PsO patients eligible for systemic therapy based on remission rates (58%, 79%, and 8%, respectively) and treatment satisfaction (90%, 99%, and 42%, respectively).

CONCLUSIONS: IPC criteria may more effectively identify patients eligible for systemic treatment based on PsO burden than physician assessments, and if adopted in clinical trials, clinical practice and reimbursement decisions may help reduce undertreatment of PsO.