International consensus definition and diagnostic criteria for generalized pustular psoriasis from the International Psoriasis Council

Key message:

The aim of this study was to develop an international consensus definition and diagnostic criteria for generalized pustular psoriasis (GPP) using a modified Delphi method. The final definition characterized HPP as a systemic inflammatory condition with cutaneous erythema and macroscopically visible sterile pustules. It may present as acutely generalized pustules or subacutely with a ring-shaped form. An important diagnostic criterion was “macroscopically visible sterile pustules on an erythematous base, not limited to the acral region or within psoriatic plaques.” These harmonized GPP criteria are intended to help clinicians make more accurate diagnoses and improve patient care.

SUMMARY

Relevance. Generalized pustular psoriasis (GPP) lacks internationally accepted definitions and diagnostic criteria, which hinders timely diagnosis and treatment, and makes it difficult to compare clinical and epidemiological studies between regions.

Target

To develop an international consensus definition and diagnostic criteria for PPG using a modified Delphi method.

Review of evidence

The rarity of HPP presents a challenge to obtaining the comprehensive published clinical data needed to develop a standardized definition and criteria. Rather than relying on a literature search, 43 statements were formulated that comprehensively address fundamental aspects of the definitions and diagnostic criteria of HPP, based on expert reviews of 64 complex cases of HPP. These statements were presented to a panel of 33 global GPP experts for voting, discussion and refinement at two virtual consensus meetings. Consensus during voting was defined as at least 80% agreement; The definition and diagnostic criteria were accepted by all panelists after voting and in-depth discussion.

Results

Thirty (91%) and 25 (76%) experts participated in the first and second rounds of the modified Delphi method. In the initial round of Delphi, consensus was reached on 53% of statements, resulting in approval of 23 statements that were used to develop proposed definitions and diagnostic criteria for HPP. A second round of Delphi resulted in a final definition: “Generalized pustular psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules.” It may occur with or without systemic symptoms, other types of psoriasis, and laboratory abnormalities. HPP can present in an acute form with generalized pustules or in a subacute form with a ring-like phenotype. The main criterion established was: “Macroscopically visible sterile pustules on an erythematous base, not limited to the acral region or within psoriatic plaques.”

Conclusions and significance

Achieving international consensus on the definition and diagnostic criteria for STH highlights the importance of collaboration, innovative methodology, and expert participation in the fight against rare diseases. Although further validation is needed, these criteria can serve as a guide for clinicians, researchers, and patients, which may lead to more accurate diagnosis and better treatment of PPG.

References:

Sue Eng Chun; Pieter van de Kerkhof; Johann E. Gudjonsson; and others

DOI: 10.1001/jamadermatol.2024.0915.

Link: https://jamanetwork.com/journals/jamadermatology/article-abstract/2818462

Fountain: BioPress