OBJECTIVES: To identify and achieve consensus on refined, specific treatment goals for GPP treatment via a Delphi panel with patient participation.

METHODS: Statements were generated based on a systematic literature review and revised by a Steering Committee. Statements were categorized into overarching principles, and short- and long-term treatment goals. A global panel of 30 dermatologists and 3 patient representatives voted in agreement or disagreement with each statement. Consensus was defined as ≥ 80% approval by the panellists.

RESULTS: Consensus was reached in the first round of voting and ≥ 90% agreement was reached for 23 of 26 statements. In summary, GPP requires a timely, tailored treatment plan, co-developed by patients and physicians, that involves a multidisciplinary approach and addresses the complexity, heterogeneity and chronicity of the disease. Short-term treatment goals should include pustule clearance within 7 days and prevention of pustule recurrence, reduction of cutaneous symptom burden (-4 or more points on the Itch and Skin Pain Numeric Rating Scale), improvement in systemic symptoms (e.g. resolution of fever within 3 days of treatment initiation and reduced fatigue), prevention of life-threatening complications and progressive improvement of inflammatory biomarkers. In patients with comorbid psoriatic diseases, treatment decisions should prioritize GPP. Long-term treatment goals should include minimizing disease activity through flare prevention and symptom control between flares, sustained disease control, management of comorbidities and improvement in quality of life (QoL). Small differences in perception between patients and physicians regarding the importance of certain treatment goals (e.g. avoiding hair and/or nail loss to improve QoL), reflect the complexity of assessing treatment goals and emphasize the need for a patient-centred approach.

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."

OBJECTIVE: To reach international consensus among psoriasis experts on a uniform dosing regimen for treatment with methotrexate in adult and pediatric patients with psoriasis and identify potential future research topics.

DESIGN, SETTING, AND PARTICIPANTS: Between September 2020 and March 2021, a survey study with a modified eDelphi procedure that was developed and distributed by the Amsterdam University Medical Center and completed by 180 participants worldwide (55 [30.6%] resided in non-Western countries) was conducted in 3 rounds. The proposals on which no consensus was reached were discussed in a conference meeting (June 2021). Participants voted on 21 proposals with a 9-point scale (1-3 disagree, 4-6 neither agree nor disagree, 7-9 agree) and were recruited through the Skin Inflammation and Psoriasis International Network and European Academy of Dermatology and Venereology in June 2020. Apart from being a dermatologist/dermatology resident, there were no specific criteria for participation in the survey. The participants worked mainly at a university hospital (97 [53.9%]) and were experienced in treating patients with psoriasis with methotrexate (163 [91.6%] had more than 10 years of experience).

MAIN OUTCOMES AND MEASURES: In a survey with eDelphi procedure, we tried to reach consensus on 21 proposals. Consensus was defined as less than 15% voting disagree (1-3). For the consensus meeting, consensus was defined as less than 30% voting disagree.

RESULTS: Of 251 participants, 180 (71.7%) completed all 3 survey rounds, and 58 participants (23.1%) joined the conference meeting. Consensus was achieved on 11 proposals in round 1, 3 proposals in round 2, and 2 proposals in round 3. In the consensus meeting, consensus was achieved on 4 proposals. More research is needed, especially for the proposals on folic acid and the dosing of methotrexate for treating subpopulations such as children and vulnerable patients.