Ultrasonography in psoriatic arthritis: which sites should we scan?

In psoriatic arthritis (PsA), ultrasonography (US) plays a growing role in the differential diagnosis and in monitoring treatment response.1 PsA is a heterogeneous disease with different domains and peculiar sites involved.2 Therefore, a dedicated US composite score is needed to monitor disease activity and to identify structural damage progression. A recently published Systematic Literature Review (SLR) identified only two US scores specifically developed for PsA (ie, 5TPD and PsA-Son) and, although these had a good sensitivity to detect inflammation and a good feasibility, they have not been validated in other series.1 3 4 Recently, the Study Group for US of the Italian Society of Rheumatology promoted the Ultrasound in PSoriatic Arthritis TREAtMent (UPSTREAM) study (registered at ClinicalTrial.gov, NCT03330769). UPSTREAM is a multicentre observational prospective cohort study and it represents the first …