Prologue: 2017 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

The 2017 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) was held in Amsterdam, the Netherlands, 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 discussion of the history, clinical features, controversies, and immunogenetics of juvenile psoriatic arthritis; updates from working groups in Outcome Measures in Rheumatology and International Dermatology Outcome Measures; a discussion of the benefits and challenges of setting up a longitudinal psoriatic arthritis (PsA) database; 3 separate discussions of the effects of the microbiome on skin and joints in psoriasis and PsA; a discussion of options for assessing joints and entheses in PsA by ultrasonography and magnetic resonance imaging; an update on GRAPPA's research and educational projects; a discussion of patient centricity, including the incorporation of patient research partners (PRP) into psoriasis and PsA research and educational efforts, from GRAPPA's PRP; and a discussion of the GRAPPA-Collaborative Research Network's inaugural meeting. In this prologue, we introduce the papers that summarize that meeting.