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Updated: Jun 6, 2026
Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Beyond Psoriasis Area and Severity Index and Body Surface Area: An Italian Delphi Consensus on the Definition of
Luigi Gargiulo1,2, Antonio Costanzo3,4, Piergiorgio Malagoli5
1Dermatology Unit, IRCCS Humanitas Research Hospital, Rozzano, Milan, Italy. luigi.gargiulo@humanitas.it.
Introduction:
Moderate psoriasis, despite its clinical relevance, remains inconsistently defined in current guidelines, leading to heterogeneous treatment decisions and variable access to systemic therapy. A unified, clinically meaningful definition is currently lacking. To establish a consensus-based, operational definition of moderate psoriasis, we conducted a two-round modified Delphi process involving expert dermatologists.
Methods:
Fifteen Italian dermatologists with recognized expertise in psoriasis participated in a Delphi survey composed of 18 statements addressing clinical severity, quality of life, symptoms, involvement of special areas, and treatment response. Consensus was defined as a median score ≥ 7 with interquartile range (IQR) ≤ 2, or ≥ 75% of ratings ≥ 7, on a scale going from 1 (completely disagree) to 10 (completely agree). Statements not reaching consensus in Round 1 were revised according to participants' comments and re-evaluated in Round 2.
Results:
In Round 1, 12 of 18 statements reached consensus. Six statements required revision owing to ambiguity or insufficient operational clarity. After refinement, including clearer definitions of early and frequent relapses, specification of Dermatology Life Quality Index (DLQI) thresholds, and explicit mention of difficult-to-treat or highly visible areas, all six statements achieved consensus in Round 2. Ultimately, consensus was obtained for all 18 statements.
Conclusions:
This Delphi process produced a comprehensive and clinically actionable definition of moderate psoriasis, emphasizing a multidimensional view of severity that extends beyond Psoriasis Area and Severity Index (PASI) or Body Surface Area (BSA). These consensus-based criteria may support earlier access to systemic therapies, including biologics and small molecules, and improve harmonization in both clinical practice and research.
Insights
A new consensus definition for moderate psoriasis was established using a Delphi process. This definition aids in consistent treatment decisions and improves access to systemic therapies for patients.
Area of Science:
- Dermatology
- Clinical Practice Guidelines
- Psoriasis Research
Background:
- Moderate psoriasis lacks a consistent definition, leading to varied treatment decisions and access to systemic therapies.
- A unified, clinically meaningful definition is needed to standardize care.
- Expert dermatologists were engaged to develop this definition.
Purpose of the Study:
- To establish a consensus-based, operational definition of moderate psoriasis.
- To address the heterogeneity in defining psoriasis severity.
- To improve clinical practice and research harmonization.
Main Methods:
- A two-round modified Delphi process involving 15 Italian expert dermatologists.
- 18 statements covering clinical severity, quality of life, symptoms, special areas, and treatment response were evaluated.
- Consensus was defined by specific scoring criteria (median score ≥7, IQR ≤2, or ≥75% ratings ≥7).
Main Results:
- Initial consensus was reached on 12 out of 18 statements in Round 1.
- Six statements were revised for clarity, addressing relapses, quality of life indices (DLQI), and specific body areas.
- Full consensus on all 18 statements was achieved after refinement in Round 2.
Conclusions:
- A comprehensive, clinically actionable definition of moderate psoriasis was developed.
- The definition adopts a multidimensional approach beyond PASI or BSA scores.
- These criteria can facilitate earlier access to systemic therapies (biologics, small molecules) and harmonize clinical practice and research.
