The role of ultrasound diagnostics in the management of patients with juvenile psoriatic arthritis

Abstract

Psoriatic arthritis (PsA) is a chronic inflammatory disease of the peripheral joints, entheses, and spine joints, affecting 10–25% of patients with psoriasis. Early diagnosis of the disease is challenging due to the possible delayed skin and joint symptoms and signs. Before the advent of ultrasound examination, the diagnosis of joint diseases was limited only to the radiological method. The ultrasound diagnosis of joint diseases in children is not established and needs a more comprehensive study.
 Materials and methods. The study included 50 PsA patients aged 3 to 17 years. We performed an ultrasound examination of 178 various joints. Knee joints were involved in 46 children, hip joints in 24, ankle joints in 34, and interphalangeal joints in 10. The mean age at onset was 7.8 years (range 1.5 to 14 years). The mean duration of the disease was 4.7 years.
 Results. Homogeneous joint effusion was the most common finding in patients with juvenile PsA (JPsA) – 83%. The effusion heterogeneity (17%) was due to hyperechoic inclusions (fibrin) in anechoic content. Diffuse synovium thickening was found in 91% of the joints. In 12.3% of joints, cartilage thinning was observed (in patients with a disease duration of 5 years or more), with fuzzy contours in some cases and normal echostructure in others.
 Conclusion. Periarticular structures, most often ligaments and tendons, are also involved in JPsA. The inflammation progresses steadily, with the rate depending on disease activity. Joint ultrasound is a reliable and highly informative method of JPsA diagnosing. It can identify a wide range of joint abnormalities; moreover, the severity of ultrasound abnormalities correlates with the disease severity, enabling using this method for monitoring disease-modifying therapy and as a screening tool for detecting the early signs of arthritis in patients with psoriasis. Joint ultrasound helps to detect early abnormalities.