International Consensus Defines Generalized Pustular Psoriasis for Clinical and Research Use

In an article published in JAMA Dermatology, an international panel of dermatology experts has achieved consensus on a standardized definition and diagnostic criteria for generalized pustular psoriasis (GPP), a rare but serious systemic inflammatory skin disorder. The effort aims to reduce diagnostic delays and improve comparability in global research on GPP, which has previously lacked universally accepted clinical parameters.

Using a modified Delphi method, the expert panel reviewed 64 challenging cases of GPP to generate 43 foundational statements addressing diagnostic features. These were refined and voted on during 2 virtual meetings involving 33 global experts. Consensus was defined as at least 80% agreement among participants.

In the first round, consensus was reached for 53% of statements, resulting in 23 accepted statements. The second round led to the final consensus definition: “Generalized pustular psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules.” The definition emphasizes that GPP can present with or without systemic symptoms, laboratory abnormalities, or coexisting psoriasis vulgaris.

A key diagnostic feature agreed upon was: “Macroscopically visible sterile pustules on erythematous base and not restricted to the acral region or within psoriatic plaques.”

The panel also distinguished between acute and subacute presentations, noting that GPP may appear as a sudden eruption of widespread pustules or present more gradually with annular patterns.

“These criteria represent a critical step forward in standardizing the diagnosis of GPP,” the authors noted. “They provide a foundation for more accurate diagnosis, better patient care, and enhanced comparability across clinical studies.”

While further validation of the criteria is required, the consensus marks a significant advancement in managing this complex and often misdiagnosed disease. Dermatologists now have a clearer reference point to recognize and treat GPP in both clinical and research settings.

Reference
Choon SE, van de Kerkhof P, Gudjonsson JE, et al. International consensus definition and diagnostic criteria for generalized pustular psoriasis from the International Psoriasis Council. JAMA Dermatol. 2024;160(7):758-768. doi:10.1001/jamadermatol.2024.0915