Ultrasonographic detection of subclinical enthesitis and synovitis: a possible stratification of psoriatic patients without clinical musculoskeletal involvement.

To evaluate the prevalence of articular/extra-articular inflammatory lesions and structural damage on ultrasonography in patients suffering from psoriasis as well as to assess possible correlations between ultrasonographic elementary lesions and clinical features.Psoriatic patients without musculoskeletal symptoms and healthy controls (HCs) were recruited. All patients received a blinded extended ultrasonographic examination of 42 joints, 12 entheses and 32 tendons. Active synovitis was defined by the presence of a grade ≥2 for grey scale (GS) and ≥1 for power Doppler (PD), while active enthesitis corresponded to entheseal hypoecogenicity in GS and entheseal PD signal (<2 mm from bone insertion).Forty psoriatic patients and 20 HCs were included. A total of 2516 joints and 712 entheses were scanned. Active synovitis was found in 11/40 (27.5%) psoriatic patients and 0/20 HCs (p=0.01). Articular synovitis (GS≥2) was more frequent in psoriasis than in HCs [34/40 (85.0%) and 11/20 (55.0%) respectively; p=0.024). Active enthesitis was found only in psoriatic patients, with a prevalence of 20.0% (8/40) (p=0.04). No significant difference in the prevalence of tenosynovitis or paratenonitis was observed between psoriatic patients and HCs. In psoriasis cohort, age was correlated with the presence of active synovitis (p=0.03), while male sex and a higher PASI score were independently correlated with the presence of active enthesitis (p=0.05 and p=0.034, respectively).Active enthesitis and synovitis could be useful to identify subclinical psoriatic arthritis. This might represent a relevant clinical step to better stratify patients with psoriasis.