Development and Validation of a Sonographic Enthesitis Instrument in Psoriatic Arthritis: The GRAPPA Diagnostic Ultrasound Enthesitis Tool (DUET) Project.

Enthesitis is a key feature in psoriatic arthritis (PsA) and may be the initial site of musculoskeletal inflammation in patients with PsA. Ultrasound (US) optimizes the detection of enthesitis, but the lack of a validated sonographic enthesitis scoring system for PsA limits the ability to conduct US-based studies of approaches to improve the early diagnosis of PsA. Creating a sonographic enthesitis scoring system that reliably identifies PsA at early stages is an important step in optimizing early diagnosis and encouraging timely interventions that will ultimately improve longterm outcomes for patients with PsA. The Group for Research and Assessment of Psoriasis and PsA (GRAPPA) US working group has set a goal of improving the evaluation of enthesitis in patients with PsA by using US through the development of a Diagnostic Ultrasound Enthesitis Tool (DUET). This article summarizes the proposed DUET study design and methodology as discussed during the 2019 GRAPPA annual meeting in Paris, France.