Prologue: 2013 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA).

The 2013 Annual Meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) was held in July 2013 in Toronto, Canada, and attended by rheumatologists, dermatologists, and representatives of biopharmaceutical companies and patient groups. We introduce the articles that summarize the meeting: A summary of a GRAPPA-organized Fellows Symposium adjacent to the 2013 European Academy of Dermatology and Venereology meeting in Istanbul; at the GRAPPA meeting proper, proceedings of a trainee symposium, where rheumatology fellows and dermatology residents presented their research; a summary of experiences and perspectives of psoriasis and psoriatic arthritis (PsA) research of 8 patient research partners with PsA who were invited to participate as delegates. Other presentations and discussions included an interactive session on composite measures of disease severity and response, including voting by GRAPPA members; a 3 part update of basic/translational/clinical science, including new bone formation, enthesitis pathophysiology, and comorbidity monitoring; a 3 part dermatology update on psoriasis outcome measures, the Brigham Scalp Nail Inverse Palmoplantar Psoriasis Composite Index, and large-scale databases; a short summary of the ongoing GRAPPA effort to update treatment guidelines for PsA; updates on several GRAPPA educational and rheumatology-related projects; and a discussion of clinical criteria to identify inflammatory arthritis, enthesitis, dactylitis, and spondylitis as distinguished from non-inflammatory conditions.