The Role of Ultrasound in Screening Subclinical Psoriatic Arthritis in Patients with Moderate to Severe Psoriasis

To identify patients in the subclinical psoriatic arthritis (Sub-PsA) phase by ultrasound (US) and provide a solution to screen them. A total of 490 participants with moderate-to-severe psoriasis were evaluated. Among them, 384 participants without arthritis symptoms were enrolled into the silent psoriasis group and 106 participants with arthritis symptoms, called prodromal/active PsA phase, were enrolled into the clinical PsA group. Another 80 non-psoriasis participants were enrolled into the control group. Each participant received clinical assessments and US examinations of 60 joints, 38 tendons, and 40 entheses. We compared the incidences of synovio-enthesitis, synovitis, tenosynovitis, erosion, and dactylitis detected on US among the three groups. Subsequently, on the basis of significant US findings, we distinguished Sub-PsA from psoriasis alone (PsO) in the silent psoriasis group and analyzed the clinical characteristics, mainly including basic clinical characteristics, body surface area (BSA), and Psoriasis Area and Severity Index (PASI) score. Only synovio-enthesitis significantly differed between the control group and the silent psoriasis group (1.3 • Synovio-enthesitis on ultrasound was significantly associated with subclinical psoriatic arthritis, especially in the lower limbs. • Routine ultrasound evaluation could help screen psoriasis patients in the subclinical psoriatic arthritis phase, which was as high as 12.7