Role of ultrasound in the interception of psoriatic arthritis in patients with psoriasis.

Skin psoriasis (PsO) often precedes the development of psoriatic arthritis (PsA), with a PsO to PsA conversion rate of about 1.5-2% per year. A careful observation of the PsO patients may allow early detection, treatment, and maybe even prevention, of the rheumatic condition. In PsA patients, musculoskeletal ultrasound (MSK-US) imaging can be used to investigate the presence of enthesitis, synovitis, tenosynovitis, and paratenonitis and this imaging technique has been shown to be more sensitive than clinical examination. MSK-US may reveal the presence of synovial and entheseal inflammation even in PsO patients without musculoskeletal symptoms and these findings might be considered indicative of subclinical PsA, although a clinical evaluation is essential to prevent overdiagnosis and overtreatment. This narrative review provides an overview of the transition from PsO to PsA with a focus on the value of US examination in this context.