International Consensus Definition and Diagnostic Criteria for Generalized Pustular Psoriasis From the International Psoriasis Council.

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.

PAPRIKA: A Question Bank for Assessing Psoriatic Arthritis Risk in Individuals of Diverse Ancestries.

OBJECTIVE: We aimed to create a question bank about clinical factors for predicting the diagnoses of psoriatic arthritis in patients with psoriasis of various ancestries and skin tones, which can be completed entirely by patients. METHODS: Utah Psoriasis Initiative participants without a psoriatic arthritis diagnosis at enrollment were observed for diagnosis during the study period. We inferred ancestry from exome sequencing data and performed Cox proportional hazards regression to identify clinical predictors of psoriatic arthritis in different ancestry groups. Based on results and literature review, we developed a question bank for assessing psoriatic arthritis risk among patients with psoriasis in various ancestries. RESULTS: Patient-reported untreated psoriasis induration and history of fingernail psoriasis were associated with psoriatic arthritis in participants of European and non-European ancestry. We developed the Psoriatic Arthritis Prediction and Identification Question Bank for Diverse Ancestries (PAPRIKA) version 1.0, which included questions regarding psoriasis characteristics, arthritis symptoms, comorbidities, family history, and demographics. PAPRIKA is accessible at http://bjfenglab.org/. CONCLUSION: The clinical features (untreated psoriasis induration and history of fingernail psoriasis) that can predict psoriatic arthritis in European individuals also work for non-European individuals. PAPRIKA can be used to gather psoriatic arthritis predictive data from patients with psoriasis without provider assistance and is relevant for patients across ancestries.

Real-world effectiveness of risankizumab in patients with moderate-to-severe psoriasis using the CorEvitas Psoriasis Registry.

BACKGROUND: Psoriasis, an inflammatory skin disease, is often treated with biologic therapeutics. OBJECTIVE: To determine the real-world treatment effectiveness of risankizumab, an interleukin-23 inhibitor, in the treatment of moderate-to-severe plaque psoriasis. METHODS: A retrospective, observational study was conducted using the CorEvitas Psoriasis Registry for eligible adults with a diagnosis of moderate-to-severe psoriasis and persistent use of risankizumab at 12 (±3) months after initiation. Skin clearance measures and patient-reported outcomes were analyzed for the entire study population and by prior biologic treatment. RESULTS: Among 287 patients with persistent risankizumab use at 1 year, most achieved clear or clear/almost clear skin and reported significant reductions in Dermatology Life Quality Index scores, psoriasis symptoms (fatigue, skin pain, and overall itch), and work and activity impairment. LIMITATIONS: The CorEvitas Psoriasis Registry is not necessarily representative of all adults with psoriasis in the United States and Canada and does not measure patient adherence. CONCLUSION: Patients treated with risankizumab, regardless of prior treatment, achieved high levels of clear and clear/almost clear skin, Dermatology Life Quality Index scores of 0/1, and significant reductions in psoriasis symptoms (fatigue, skin pain, and overall itch) and work and activity impairment 1 year after initiation.

The Effectiveness of Guselkumab by BMI Category Among Patients with Moderate-to-Severe Plaque Psoriasis in the CorEvitas Psoriasis Registry.

INTRODUCTION: Prior studies have demonstrated guselkumab improves disease activity and patient-reported outcomes (PROs) among patients with moderate-to-severe plaque psoriasis. However, the real-world effectiveness of guselkumab across different subgroups [e.g., body mass index (BMI) categories] remains an area of active research. METHODS: This study included patients enrolled in the CorEvitas Psoriasis Registry between July 18, 2017 and March 10, 2020 who had moderate-to-severe psoriasis [Investigator's Global Assessment (IGA) score ≥ 3], initiated guselkumab at a registry visit (index date), and had a follow-up registry visit after persistent guselkumab therapy for 9-12 months. Patients were stratified into three BMI categories: obese (≥ 30 kg/m2), overweight (25- < 30 kg/m2), and underweight/normal weight (< 25 kg/m2). Response rates and mean changes for disease activity outcomes and PROs at follow-up were assessed within each BMI category. RESULTS: Of the 180 patients included in the study, 101 (56%) were obese, 52 (29%) were overweight, and 27 (15%) were underweight/normal weight. Among the obese, overweight, and underweight/normal weight patients, 57%, 58%, and 72%, respectively, achieved an IGA score of 0/1 after 9-12 months of persistent guselkumab treatment. An IGA score of 0 was achieved by 33%, 35%, and 48% of obese, overweight, and underweight/normal weight patients, respectively. A 90% improvement in the Psoriasis Area and Severity Index was achieved by 46%, 46%, and 56% in these respective subgroups. Mean improvements in disease activity and PRO scores were similar among BMI subgroups. CONCLUSION: The results of this real-world study showed improvements in disease severity and several PRO scores within all BMI categories among patients with moderate-to-severe psoriasis treated with guselkumab. These unadjusted findings suggest that obese and overweight patients have comparable absolute improvements to those with lower BMI; however, they may be less likely to achieve relative endpoints. Additional analyses are needed to fully characterize this relationship.

Real-World Effectiveness of 9-12 Months of Guselkumab Therapy among Patients with Moderate-to-Severe Plaque Psoriasis in the CorEvitas Psoriasis Registry.

INTRODUCTION: Guselkumab, an anti-interleukin-23 biologic therapy, has been shown to significantly reduce disease activity and improve patient-reported outcome measures (PROMs) among patients with moderate-to-severe plaque psoriasis in clinical trials. However, characterization of the real-world effectiveness of guselkumab among patients living in the USA and Canada is warranted. METHODS: Patients who participated in the CorEvitas Psoriasis Registry between 18 July 2017 and 10 March 2020 were included if they met the following criteria: Investigator's Global Assessment (IGA) score ≥ 3 and body surface area (BSA) ≥ 10% (moderate-to-severe psoriasis), initiated guselkumab at a registry (index) visit, and had a registry follow-up visit after 9-12 months of persistent guselkumab therapy. Data were retrieved for baseline patient demographics and disease characteristics, treatment history, disease activity, and PROMs. Outcomes were assessed at index and follow-up visits; response rates and mean changes were calculated. RESULTS: Among 113 patients, mean age was 49.7 years, mean psoriasis duration was 17.5 years, and 65.5% of patients were biologic experienced. At baseline, mean IGA score was 3.3, Psoriasis Area Severity Index (PASI) score was 13.6, and Dermatology Life Quality Index (DLQI) score was 9.6. At follow-up, IGA 0/1, PASI 90, and DLQI 0/1 were achieved by 62.2%, 56.8%, and 54.7% of patients, respectively. Statistically significant improvements were observed in all disease activity scores and PROMs, including the EuroQoL Visual Analogue Scale, Work Productivity and Activity Impairment, Patient Global Assessment, fatigue, skin pain, and itch (p < 0.05). CONCLUSIONS: This real-world study showed that patients with moderate-to-severe psoriasis who received 9-12 months of persistent guselkumab therapy experienced improvements in disease severity and PROMs.

Effectiveness of Guselkumab Therapy among Patients with Plaque Psoriasis with Baseline IGA Score ≥ 2 in the CorEvitas Psoriasis Registry.

INTRODUCTION: In clinical trials, treatment with the interleukin-23 inhibitor guselkumab was associated with significantly improved disease severity and patient-reported outcome measures (PROMs) among patients with moderate-to-severe plaque psoriasis. However, limited information is available regarding the real-world effectiveness of guselkumab among patients with psoriasis of mild, moderate, and severe Investigator's Global Assessment (IGA) severities living in the USA and Canada. METHODS: Patients participating in the CorEvitas Psoriasis Registry between 18 July 2017 and 10 July 2019 who met the following criteria were included: IGA ≥ 2 (mild or greater disease severity), initiated guselkumab at a registry (index) visit, and had a registry follow-up visit after persistent guselkumab treatment for 9 to 12 months. Data were collected for patient demographics, disease characteristics, treatment history, disease activity, and PROMs. At follow-up, outcome measure response rates and mean changes from the index visit were calculated. RESULTS: Among 130 patients, the mean age was 50.2 years, 39.2% were female, and 56.9% had a body mass index ≥ 30 kg/m2. Mean psoriasis duration was 17.5 years and 79.2% of patients had previously received one or more biologic therapy. At the index visit, mean IGA, Psoriasis Area Severity Index (PASI), and Dermatology Life Quality Index (DLQI) scores were 3.0, 9.9, and 8.0, respectively. At follow-up, IGA 0/1 and IGA 0 were achieved by 64.6% and 36.2% of patients, respectively. PASI 75, 90, and 100 were achieved by 61.5%, 46.9%, and 36.9% of patients; 55.4% had maintained or achieved DLQI 0/1. Mean improvements were observed in all evaluated disease activity outcomes and PROMs, with all differing significantly from zero except for the percent of work hours missed due to psoriasis. CONCLUSION: In this real-world study, patients with a baseline IGA score ≥ 2 experienced improvements in disease activity and PROMs after 9-12 months of persistent guselkumab treatment.

Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA): updated treatment recommendations for psoriatic arthritis 2021.

Since the second version of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) treatment recommendations were published in 2015, therapeutic options for psoriatic arthritis (PsA) have advanced considerably. This work reviews the literature since the previous recommendations (data published 2013-2020, including conference presentations between 2017 and 2020) and reports high-quality, evidence-based, domain-focused recommendations for medication selection in PsA developed by GRAPPA clinicians and patient research partners. The overarching principles for the management of adults with PsA were updated by consensus. Principles considering biosimilars and tapering of therapy were added, and the research agenda was revised. Literature searches covered treatments for the key domains of PsA: peripheral arthritis, axial disease, enthesitis, dactylitis, and skin and nail psoriasis; additional searches were performed for PsA-related conditions (uveitis and inflammatory bowel disease) and comorbidities. Individual subcommittees used a GRADE-informed approach, taking into account the quality of evidence for therapies, to generate recommendations for each of these domains, which were incorporated into an overall schema. Choice of therapy for an individual should ideally address all disease domains active in that patient, supporting shared decision-making. As safety issues often affect potential therapeutic choices, additional consideration was given to relevant comorbidities. These GRAPPA treatment recommendations provide up-to-date, evidence-based guidance on PsA management for clinicians and people with PsA.

Efficacy and safety of apremilast in patients with mild-to-moderate plaque psoriasis: Results of a phase 3, multicenter, randomized, double-blind, placebo-controlled trial.

BACKGROUND: Patients with mild-to-moderate psoriasis may have substantial quality-of-life impairment. OBJECTIVE: To evaluate apremilast 30 mg twice daily for mild-to-moderate psoriasis. METHODS: Phase 3, double-blind, placebo-controlled study in adults with mild-to-moderate psoriasis inadequately controlled or intolerant to ≥ 1 topical psoriasis therapy (NCT03721172). The primary endpoint was the achievement of static Physician Global Assessment score of 0 (clear) or 1 (almost clear) and ≥ 2-point reduction at week 16. RESULTS: Five hundred ninety-five patients were randomized (apremilast: 297; placebo: 298). The primary endpoint was met, with a significantly greater static Physician Global Assessment response rate observed at week 16 in the apremilast group compared with the placebo group (21.6% vs 4.1%; P < .0001). All secondary endpoints were met with the achievement of body surface area-75 (33.0% vs 7.4%), body surface area ≤ 3% (61.0% vs 22.9%), ≥ 4-point reduction in Whole Body Itch Numeric Rating Scale (43.2% vs 18.6%), Scalp Physician Global Assessment 0 or 1 and ≥ 2-point reduction (44.0% vs 16.6 %), and changes from baseline in body surface area, Psoriasis Area and Severity Index, and Dermatology Life Quality Index (all P < .0001). The most commonly reported adverse events (≥ 5%) with apremilast were diarrhea, headache, nausea, nasopharyngitis, and upper respiratory tract infection, consistent with prior studies. LIMITATIONS: The study lacked an active-comparator arm. CONCLUSION: Apremilast demonstrated efficacy in mild-to-moderate psoriasis and safety consistent with the established safety profile of apremilast.

Demographics, Disease Characteristics, and Patient-Reported Outcomes Among Patients with Psoriasis Who Initiated Guselkumab in CorEvitas' Psoriasis Registry.

INTRODUCTION: Guselkumab is approved for the treatment of both moderate-to-severe plaque psoriasis and active psoriatic arthritis (PsA) in the USA. However, little is known about patients initiating guselkumab in a real-world setting. The objective of this study was to describe baseline characteristics among patients with plaque psoriasis who initiated guselkumab at or after enrollment in CorEvitas' Psoriasis Registry. METHODS: Adult patients who initiated guselkumab in the Psoriasis Registry between July 18, 2017 and November 6, 2018 were included. Demographics, disease characteristics, and patient-reported outcome measures (PROMs) were assessed at the time of guselkumab initiation (baseline). Patients with psoriasis were stratified according to the number of previously received biologics (0 to 4+) for comparison. A subset of patients with psoriasis and concomitant dermatologist-diagnosed PsA were stratified into biologic-naïve and biologic-experienced groups. RESULTS: Among 687 patients with psoriasis who initiated guselkumab, biologic-naïve patients and those with four or more prior biologics had the most severe disease and the worst PROM scores at baseline. Among 251 patients with concomitant dermatologist-diagnosed PsA, biologic-naïve patients had more severe disease and worse PROM scores than biologic-experienced patients. CONCLUSIONS: These findings highlight important differences in baseline characteristics according to biologic experience among patients with plaque psoriasis with or without concomitant PsA initiating guselkumab in a real-world setting.

Pustular Psoriasis and Associated Musculoskeletal Disorders.

Pustular psoriasis (PsO) is an uncommon variant of PsO that may present in a generalized or localized fashion with or without musculoskeletal or systemic inflammatory involvement. Generalized pustular PsO (GPP) presents as a widespread acute or subacute pustular eruption that may be familial and is often associated with severe flares and systemic inflammation. The palmoplantar pustulosis variant is localized to palms and soles, whereas acrodermatitis continua of Hallopeau is localized to the nail apparatus. Patients with pustular PsO may have overlapping plaque PsO and may develop psoriatic arthritis (PsA). Pustulosis is also a feature of both synovitis, acne, pustulosis, hyperostosis, osteomyelitis (SAPHO) syndrome and chronic nonbacterial osteomyelitis. At the 2020 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) annual meeting, members were given an overview of the cutaneous features of pustular PsO, SAPHO, and recent insights into the genetics of GPP, leading to new targeted drug therapies and the development of validated endpoints.

Psoriasis and Psoriatic Arthritis in the Context of the COVID-19 Pandemic: A Plenary Session From the GRAPPA 2020 Annual Meeting.

The coronavirus disease 2019 (COVID-19; caused by SARS-CoV-2) pandemic has affected the healthcare system on a global scale, and we utilized the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2020 annual meeting to examine how COVID-19 might affect patients with psoriatic disease (PsD) and the clinicians who care for them. Pressing issues and concerns identified included whether having psoriasis increased the risk of acquiring COVID-19, vaccine safety, and the acceptability of telehealth. The general message from rheumatologists, dermatologists, infectious disease specialists, and patient research partners was that data did not suggest that having PsD or its treatment significantly increased risk of infection or more severe disease course, and that the telehealth experience was a success overall.

Instruments Measuring Physical Function for Psoriatic Arthritis Endorsed at GRAPPA 2020 Annual Meeting: Updates of the GRAPPA-OMERACT Working Group.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)-Outcome Measures in Rheumatology (OMERACT) Psoriatic Arthritis (PsA) Working Group provided updates at the 2020 GRAPPA annual meeting on its work toward developing a core outcome set for PsA. Working groups were set up for the 4 prioritized domains: enthesitis, fatigue, structural damage, and physical function. Two instruments for measurement of physical function were provisionally endorsed: (1) the Health Assessment Questionnaire-Disability Index and (2) the physical functioning domain in the Medical Outcomes Study 36-item Short Form survey.

Prologue: 2020 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) held its annual meeting in 2020 in an online format due to travel restrictions during the coronavirus disease 2019 (COVID­19; caused by SARS-CoV-2) pandemic. The virtual meeting was attended by 351 rheumatologists, dermatologists, representatives of biopharmaceutical companies, and patient research partners. Similar to previous years, GRAPPA's annual meeting focused on the 3 overlapping missions of education, research, and clinical care of psoriatic disease. Trainee sessions this year included the annual trainee symposium and a grant-writing workshop. Plenary sessions included updates on COVID-19 and psoriatic disease from multispecialty and patient perspectives, and updates on pustular psoriasis and associated musculoskeletal manifestations. Progress on research and updates were presented for the following groups: Collaborative Research Network, Outcome Measures in Rheumatology (OMERACT) Psoriatic Arthritis Working Group, International Dermatology Outcome Measures, Composite Measures, Education Committee, and Treatment Guidelines. New this year were 3 concurrent workshops on ultrasound assessment of joints and entheses, magnetic resonance imaging of psoriatic arthritis, and pustular psoriasis efficacy endpoints; 6 "Meet the Expert" sessions; and facilitated "poster tours." In our prologue, we introduce the papers that summarize this meeting.

Characterization of Patients with Psoriasis in Challenging-to-Treat Body Areas in the Corrona Psoriasis Registry.

BACKGROUND: Real-world studies evaluating patients with challenging-to-treat localizations of psoriasis (scalp, nail, and palmoplantar) are limited. OBJECTIVE: To characterize patients with versus without psoriasis in challenging-to-treat areas seen in routine US clinical practice. METHODS: This retrospective observational study included all adult patients with psoriasis enrolled in the Corrona Psoriasis Registry between April 2015 and May 2018 who initiated a biologic therapy at registry enrollment. Patients were stratified by the presence of scalp, nail, or palmoplantar psoriasis (nonmutually exclusive groups). Patient demographics, clinical char-acteristics, disease activity, and patient-reported outcome measures (pain, fatigue, itch, EuroQol visual analog scale [EQ VAS], Dermatology Life Quality Index [DLQI], and Work Productivity and Activity Impairment questionnaire [WPAI]) were assessed at registry enrollment and compared between patients with versus without each challenging-to-treat area using nonparametric Kruskal-Wallis tests for continuous variables and χ2 or Fisher exact tests for categorical variables. Generalized linear regression models were used to estimate differences in disease activity and patient-reported outcomes between patients with versus without each challenging-to-treat area. RESULTS: Among 2,042 patients with psoriasis (mean age [±SD], 49.6 ± 14.7 years; 51.5% male), 38.4% had psoriatic arthritis (PsA), 38.1% had scalp psoriasis, 16.0% had nail psoriasis, 10.9% had palmoplantar psoriasis, and 26.2% had a combination of ≥2 challenging-to-treat areas and PsA; only 34.2% had body plaque psoriasis without PsA or challenging-to-treat areas. Patients in all challenging-to-treat groups reported higher (mean [95% CI]) itch (scalp, 58.01 [57.62-58.40] vs. 54.35 [53.99-54.72]; nail, 56.42 [56.02-56.81] vs. 55.59 [55.20-55.97]; palmoplantar, 60.22 [59.86-60.59] vs. 55.15 [54.79-55.54]) and lower EQ VAS (scalp, 68.12 [67.78-68.48] vs. 69.46 [69.12-69.81]; nail, 66.21 [65.89-66.55] vs. 69.48 [69.14-69.83]; palmoplantar, 66.21 [66.07-66.75] vs. 69.29 [68.94-69.94]) scores than those without the respective challenging-to-treat localization. Patients with nail or palmoplantar psoriasis reported higher pain, fatigue, and DLQI scores than those without. Higher proportions of patients with scalp or palmoplantar psoriasis reported work impairment compared with those without. CONCLUSION: Two-thirds of patients with psoriasis who initiated biologic therapy had PsA and/or ≥1 challenging-to-treat area. Patients with challenging-to-treat areas had worse patient-reported outcome scores than those without, indicating a significant burden of challenging-to-treat areas on patients' quality of life.

Examination of Treatment Satisfaction Instruments in Psoriasis: 2017 Results from the Psoriasis Working Group of the International Dermatology Outcome Measures (IDEOM).

BACKGROUND/AIMS: In dermatology clinical trials, assessment of patients' treatment satisfaction is crucial but often lacking. To address this need, IDEOM's Psoriasis Working Group seeks to evaluate, develop, and validate treatment satisfaction instruments for the psoriasis population. The Psoriasis Working Group aimed to determine (1) factors affecting psoriasis patients' satisfaction with their therapies, (2) adequacy of two commonly used generic treatment satisfaction instruments in reflecting the psoriasis patients' perspective, and (3) whether a need exists to develop a new treatment satisfaction instrument. METHODS: Patient perspectives on satisfaction with treatment efficacy, safety, convenience, and overall satisfaction were elicited.Stakeholders were presented with information regarding the feasibility and content validity of two generic treatment instruments, the Treatment Satisfaction Questionnaire for Medication (TSQM) and the Treatment Satisfaction with Medicines Questionnaire (SATMED-Q). We conducted a nominal group discussion and survey to determine whether stakeholders considered these instruments feasible and adequate to address treatment satisfaction for psoriasis therapies. RESULTS: Forty-five stakeholders participated in the nominal group discussion and survey. 53% of participants voted that the TSQM and SATMED-Q are not adequate and that we should create a new dermatology-specific treatment satisfaction instrument. Patients and other stakeholders also provided feedback on aspects of treatment satisfaction important to them. These include speed of onset and durability of therapeutic effect of a medication, permanence of side effects, and convenience of administering the medication. CONCLUSION: Stakeholders, including patients and providers, determined that generic treatment satisfaction questionnaires are not adequate to evaluate treatment satisfaction in psoriasis patients.

Prologue: 2019 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

The 2019 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) was held in Paris, France, and was attended by rheumatologists, dermatologists, representatives of biopharmaceutical companies, and patients. As in previous years, GRAPPA members held a symposium for trainees to discuss their research in psoriatic disease with experts in the field. Other subjects featured during the annual meeting included a composites workshop to review continuous composite measures; the GRAPPA-Collaborative Research Network's third annual meeting; the need for a precision medicine approach to the treatment of psoriatic disease; updates from working groups in International Dermatology Outcome Measures and Outcome Measures in Rheumatology; a debate on the effectiveness of methotrexate in the treatment of psoriatic arthritis (PsA); updating recommendations for optimal treatment approaches for patients with PsA; an update on GRAPPA's research and educational projects; and the GRAPPA ultrasound (US) working group's goal to optimize the evaluation of enthesitis in patients with PsA using US through the development of a diagnostic US enthesitis tool. In this Prologue, we introduce the papers that summarize that meeting.

Proceedings of the 2019 GRAPPA Collaborative Research Network Meeting.

At the 2019 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis-Collaborative Research Network annual meeting, the group presented its progress in selecting a database platform; items to include in an electronic case report form (eCRF); and standardized operating procedures (SOP) for the collection, processing, storage, and transport of biomaterial. A pilot investigator-initiated study was also proposed that, in addition to addressing an area of unmet need, would allow for the testing of both the eCRF and SOP.

Methotrexate in Psoriasis and Psoriatic Arthritis.

Methotrexate (MTX) is the most commonly prescribed first-line therapy in psoriatic arthritis (PsA) internationally and is also commonly used in the treatment of psoriasis. However, data supporting its use in PsA are limited and significant toxicities can occur. This article summarizes a debate at the 2019 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) annual meeting that focused on the use of MTX in psoriasis and PsA. Four clinicians and 1 patient research partner presented clinical study data and the patient experience summarizing the efficacy, tolerability, and toxicity of MTX for both skin and musculoskeletal manifestations. A survey of attending GRAPPA members collected data on current and planned future use of MTX across the world.

The GRAPPA-OMERACT Working Group: 4 Prioritized Domains for Completing the Core Outcome Measurement Set for Psoriatic Arthritis 2019 Updates.

The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA)-Outcome Measures in Rheumatology (OMERACT) Psoriatic Arthritis (PsA) working group provided updates at the 2019 GRAPPA annual meeting on its work toward developing a core outcome set for PsA. The working group prioritized 4 domains, including musculoskeletal disease activity (enthesitis and dactylitis), fatigue, physical function, and structural damage. In this report, the working group summarizes its progress in standardizing the core outcome set for these 4 domains.