Prevalence of ultrasound and clinical findings suggestive of inflammatory arthritis in children with skin psoriasis. Reply

To evaluate the prevalence of clinical and ultrasound (grey-scale and Doppler) abnormalities in joints, periarticular structures and nails of children affected by skin psoriasis (PsO).Cross-sectional study including consecutive children affected by PsO. A systematic clinical and ultrasound evaluation of joints, entheses, tendons and nails were performed by independent examiners blinded to each other assessment.57 Children: 26 girls (46%), mean age of 9 ± 4 years, divided into two groups, asymptomatic (Asy, 42 children) and symptomatic (Sy, 15 children) according to musculoskeletal pain. Differences were observed between the two groups in relation to age (9 ± 3 in Asy vs 11 ± 4 yrs in Sy, p< 0.05), PsO duration (2.4 ± 2.4 vs 5.4 ± 3.9 yrs, p< 0.001), systemic treatment (23 [54.8%] vs 2 [13.3%], p< 0.01), tender joint count (0 vs 12 children [80%], p< 0.001), swollen joint count (0 vs 3 [20%], p< 0.01) and entheseal pain (0 vs 10 [66.7%], p< 0.001). Ultrasound evaluation showed statistically significant differences between Asy and Sy groups for the presence of ultrasound abnormalities (16/42 [38%] vs 12/15 [80%]), synovitis (1/42 [2%] vs 4/15 [25%]) and enthesitis (4/42 [9.5%] vs 5/15 [33%]). Three children in the Sy group were classified with juvenile psoriatic arthritis (JPsA).Ultrasound abnormalities were higher in the Sy group with synovitis and enthesitis as the most prevalent findings. Asy patients were more frequently under systemic treatment. Ultrasound and a systematic clinical evaluation are useful tools for detecting subclinical JPsA in children with PsO and musculoskeletal symptoms.