Additional Value of Ultrasound in Patients with Psoriatic Arthritis within Treatment Target.

In psoriatic arthritis (PsA), musculoskeletal ultrasound is a complementary tool to physical examination, useful even in patients in remission to detect subclinical activity. The objective of the study was to assess the ultrasound prevalence of active enthesitis and synovitis in patients who reached the therapeutic target. This cross-sectional study included patients with at least 6 months of therapy with a targeted synthetic or biological disease-modifying antirheumatic drug who were in treatment target (i.e., DAPSA < 14). Patients underwent bilateral clinical and ultrasound examination of the elbow lateral epicondyle, quadriceps insertion, distal patellar tendon insertion, and Achilles enthesis for assessing enthesitis, and hand and foot joints for assessing synovitis. Enthesitis and synovitis were considered active if the power Doppler signal showed at least a score of one. The study included 51 PsA patients, women (52.9%), with an average age of 55 years. Although the patients were within the DAPSA treatment target, 21.6% had at least one painful enthesis at clinical examination, 19.6% had ultrasound evidence of at least one active enthesitis and 15.7% had ultrasound signs of at least one active synovitis. Among PsA patients thought to be within the therapeutic target, ultrasound detected a non-negligible percentage of active enthesitis and synovitis.