Re-Categorization of Psoriasis Severity: Delphi Consensus from the International Psoriasis Council

Abstract Background Psoriasis severity categories have been important tools for clinicians to use in treatment decisions as well as to determine eligibility criteria for clinical studies. However, due to the heterogeneity of severity classifications and their lack of consideration for the impact of psoriasis involvement of special areas or past treatment history, patients may be mis-categorized, which can lead to under-treatment of psoriasis. Objective To develop a consensus statement on the classification of psoriasis severity. Methods A modified Delphi approach was developed by the International Psoriasis Council to define psoriasis severity. Results After completion of the exercise, seven severity definitions were preferentially ranked. This most preferred statement rejects the mild, moderate and severe categories in favor of a dichotomous definition: Psoriasis patients should be classified as either candidates for topical therapy or candidates for systemic therapy; the latter are patients who meet at least one of the following criteria: 1) BSA > 10%, 2) Disease involving special areas, 3) Failure of topical therapy. Limitations This effort might have suffered from a lack of representation by all relevant stakeholders, including patients. Conclusion The consensus statement describes two categories of psoriasis severity, while accounting for special circumstances where patients may require systemic therapy.