Development and validation of a pediatric internationally agreed ultrasound knee synovitis protocol (PIUS-knee) by the PReS imaging working party.

Objectives: To identify an optimal pediatric musculoskeletal ultrasound (MSUS) protocol for the detection of knee arthritis in patients with juvenile idiopathic arthritis (JIA) including a comparison with existing protocols. Secondary aims were to correlate MSUS-identified B-Mode (BM) and Power Doppler-Mode (PD) synovitis with clinical findings.

Methods: Consecutive JIA patients with confirmed knee arthritis after clinical examination underwent a thorough MSUS study protocol which included views identified and consented by the Pediatric Rheumatology european Society (PReS) Imaging Working Party for the detection of synovitis.

Infection with SARS-CoV-2 causes flares in patients with juvenile idiopathic arthritis in remission or inactive disease on medication.

Background: Flares of juvenile idiopathic arthritis (JIA) have been described in the context of various infections. Flares of rheumatic diseases in adults have been described following infection with SARS-CoV-2 in several cohorts. So far, the effect of infection with SARS-CoV-2 on the course of JIA is unknown.

Salivary gland ultrasound in the diagnostic workup of juvenile Sjögren's syndrome and mixed connective tissue disease.

Background: Juvenile Sjögren's Syndrome (jSS) is a rare phenomenon that may appear as primary jSS or associated with mixed connective tissue disease (MCTD) and other autoimmune diseases as secondary jSS. With currently no standard diagnostic procedures available, jSS in MCTD seems to be underdiagnosed. We intended to describe and identify similar distinct salivary gland ultrasound (SGUS) findings in a cohort of primary and secondary jSS patients, focusing on sicca like symptoms and glandular pain/swelling in the patients'history.

Correction to: Age dependent ultrasound B-mode findings of the elbow joint in healthy children and adolescents.

The Second author's name was incorrectly published in the original article. The correct name is Hartwig Wilhelm Lehmann.