SAT0499 PREVALENCE OF ULTRASOUND FINDINGS SUGGESTIVE OF INFLAMMATORY ARTHRITIS IN CHILDREN WITH SKIN PSORIASIS (ChildEchoPso)
Authors: L. Coronel, T. Gudu, S. Ruel-Gagné, H. Gouze, F. Vidal, I. Padovano, F. Constantino, M. Breban, E. Mahe, M. A. D’agostino
Journal: Annals of the Rheumatic Diseases (2020)

Background: The prevalence of psoriasis (PsO) in children is estimated between 0.5-1% (1), and can be associated with muskuloskeletal involvement, although the prevalence and typology of such involvement is unknown. (2) Over the last years ultrasound associated with Doppler (PDUS) has become an important tool for evaluating joint involvement in children with Juvenile Inflammatory arthritis (JIA). Several studies have shown the high sensitivity of this technique for detecting joint involvement, as well as high acceptability, due to the lack of radiation or of sedation (3). Objectives: To evaluate the prevalence of joints and entheses involvement in children affected by PsO. Methods: Observational cross-sectional study aiming at evaluating 150 consecutive children (≤16 years) affected by skin PsO and addressed by a dermatologist. For each child a standardized clinical and ultrasound evaluation of joint and entheses is performed at the following bilateral sites: a) Entheses: quadriceps tendon, proximal and distal patellar ligament, Achilles tendon, plantar fascia and extensor elbow tendon), b) joints: metacarpophalangeal, proximal and distal interphalangeal, wrist, elbow, knee, ankle, and metatarsophalangeal. PDUS evaluation is performed by an independent examiner, blinded to the clinical assessment of each subject. Results: 41 patients were included until now, where 9 patients presented some kind of symptom (painful joint or enthesis), 24 patients have family history of psoriasis and none of them had family history of psoriatic arthritis. Demographic and clinical characteristics are shown in table 1, whilst PDUS findings in Table 2. Table 1. Demographic and clinical characteristics: Total (n=41) Asymptomatic (n=32) Symptomatic (n=9) p Males 22 (53.7%) 18 (56.3%) 4 (44.4%) NS Age 9.4 ± 3.9 8.91 ± 3.5 11.3 ± 4.6 NS Pso duration (years ) 3.5 ± 3.4 2.9 ± 2.9 5.6 ± 4.5 &lt;0.05 PASI 5 ± 4.3 4.8 ± 4.5 5.7 ± 3.56 NS BSA 4.3 ± 3.9 4.47 ± 4.3 4.1 ± 2.26 NS Nail involvement 25 (61%) 19 (59.4%) 6 (66.7%) NS Plaques psoriasis 20 (48.8%) 14 (43.8%) 6 (66.7%) NS TJC ≥1, n/tot (% ) 9 (22% ) 0 (0 ) 9 (100% ) &lt;0.001 SJC ≥1, n/tot (% ) 2 (4.9% ) 0 (0 ) 2 (22.2% ) &lt;0.05 Entheseal pain, n/tot (% ) 6 (14.6% ) 0 (0 ) 6 (66.7% ) &lt;0.001 Dactylitis 0 0 0 NA PASI: Psoriasis area severity index. BSA: Body surface area. TJC: Tender Joint Count. SJC: Swollen Joint Count. Table 2 PDUS Findings: Patients Total (n=41) Asymptomatic (n=32) Symptomatic (n=9) p ≥1 ultrasound abnormality, n/tot (%) 19 (46.3%) 13 (40.6%) 6 (66.7%) NS ≥1 joint effusion, n/tot (%) 11 (26.8%) 9 (28.1%) 2 (22.2%) NS ≥1 synovitis, n/tot (%) 3 (7.3%) 1 (3.1%) 2 (22.2%) NS ≥1enthesitis, n/tot (% ) 7 (17.1% ) 3 (9.4% ) 4 (44.4% ) &lt;0.05 ≥1 tenosynovitis, n/tot (%) 0 (0) 0 (0) 0 (0) NA ≥1 nail with modified structure, n/tot (%) 22 (53.7%) 19 (59.4%) 3 (33.3%) NS Conclusion: This study shows that the presence of ultrasound abnormalities was higher in the symptomatic group and considering the fact that the most frequent inflammatory ultrasound finding was enthesitis, we might consider the enthesis as a possible landmark for developing juvenile psoriatic arthritis. References: [1]Michalek et al. J Eur Acad Dermatol Venereol, 2017 [2]Petty et al. J Rheumatol, 2004 [3]Buchmann et al. Radiol Clin N Am, 2004 Acknowledgments: This research was conducted while Luis Coronel was a PARTNER Fellow Disclosure of Interests: None declared