Subclinical synovitis and enthesitis in psoriasis patients and controls by ultrasonography in Saudi Arabia; incidence of psoriatic arthritis during two years.

Objective: To evaluate ultrasonographic subclinical inflammatory synovitis and enthesitis in psoriasis patients, without clinical arthritis or enthesitis compared with healthy controls, with a 2-year follow-up to study the associated incidence of psoriatic arthritis (PsA).

Methods: A total of 109 consecutive psoriasis vulgaris patients without clinical signs of PsA and 90 healthy controls were included from two tertiary medical centers. Subjects underwent dermatological examination, PASI score evaluation for severity of psoriasis, musculoskeletal examination using 68/66 joints count for tenderness and swollen joints.