International Consensus Definition and Diagnostic Criteria for Generalized Pustular Psoriasis From the International Psoriasis Council
Authors: Siew Eng Choon, Peter van de Kerkhof, Johann E. Gudjonsson, Claudia de la Cruz, Jonathan Barker, Akimichi Morita, Ricardo Romiti, Azura Mohd Affandi, Pravit Asawanonda, Arthur David Burden, César Gonzalez, Slaheddine Marrakchi, Mohammad Rafiqul Mowla, Yukari Okubo, Hazel H. Oon, Tadashi Terui, Tsen-Fang Tsai, Kristina Callis-Duffin, Hideki Fujita, Seong Jin Jo, Joseph Merola, Ulrich Mrowietz, Lluïs Puig, Diamant Thaçi, Margarita Velásquez, Matthias Augustin, Mahira El Sayed, Alexander A. Navarini, Andrew Pink, Jörg Prinz, Hamida Turki, Renata Magalhães, Francesca Capon, Hervé Bachelez, Maryem Aboudourib, Aryani Adji, Jahangir Alam, Abdelrahman Alwakeel, Emna Bahloul, Jaquelini Barboza da Silva, Deva Pratim Barua, Andrea Chiricozzi, Leena Chularojanamontri, Ahmed Dadoo, Menno de Rie, Mohamed El-Komy, Beatrice Etemesi, Chowdhury Farhana, Paolo Gisondi, Bryan Guevara, Mohammed Huq, Denis JULLIEN, Jo Lambert, Leandro Leite, Mohammad Rafiqul Mowla, Miranti Pangastuti, Solange Reynoso, Narumol Silpa-archa, Tiago Torres, Lily Lyralin Tumalad, Kazuki Yatsuzuka, Carmen Yris Taveras, Yihui Yu, Xibao Zhang
Journal: JAMA Dermatology (2024)

Importance Generalized pustular psoriasis (GPP) lacks internationally accepted definitions and diagnostic criteria, impeding timely diagnosis and treatment and hindering cross-regional clinical and epidemiological study comparisons. Objective To develop an international consensus definition and diagnostic criteria for GPP using the modified Delphi method. Evidence Review The rarity of GPP presents a challenge in acquiring comprehensive published clinical data necessary for developing standardized definition and criteria. Instead of relying on a literature search, 43 statements that comprehensively addressed the fundamental aspects of the definitions and diagnostic criteria for GPP were formulated based on expert reviews of 64 challenging GPP cases. These statements were presented to a panel of 33 global GPP experts for voting, discussion, and refinements in 2 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. Findings In the first and second modified Delphi round, 30 (91%) and 25 (76%) experts participated. In the initial Delphi round, consensus was achieved for 53% of the statements, leading to the approval of 23 statements that were utilized to develop the proposed definitions and diagnostic criteria for GPP. During the second Delphi round, the final definition established was, “Generalized Pustular Psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules.” It can occur with or without systemic symptoms, other psoriasis types, and laboratory abnormalities. GPP may manifest as an acute form with widespread pustules or a subacute variant with an annular phenotype. The identified essential criterion was, “Macroscopically visible sterile pustules on erythematous base and not restricted to the acral region or within psoriatic plaques.” Conclusions and Relevance The achievement of international consensus on the definition and diagnostic criteria for GPP underscores the importance of collaboration, innovative methodology, and expert engagement to address rare diseases. Although further validation is needed, these criteria can serve as a reference point for clinicians, researchers, and patients, which may contribute to more accurate diagnosis and improved management of GPP.