<p>This review will summarize clinical, genetic and pathophysiologic characteristics that are shared between children with enthesitis related arthritis (ERA) with axial involvement and adults with non-radiographic, and in some cases radiographic, axial spondyloarthritis (SpA); and between children with ERA and primarily peripheral disease manifestations and adults with peripheral SpA. Due to the differences in classification criteria for children with ERA and adults with axial and peripheral SpA, the FDA granted automatic full waivers of studies in children for new medications for "axial spondyloarthropathies including ankylosing spondylitis" up until July 2020. Thus, although current juvenile idiopathic arthritis (JIA) treatment guidelines recommend the use of biologic disease modifying anti-rheumatic drugs (DMARDs) as part of the early treatment for patients with ERA, none of the FDA-approved therapies for peripheral SpA or non-radiographic axial SpA (certolizumab pegol, ixekizumab, and secukinumab) have been studied or are labelled for use in children with ERA. Considering the similarities between adult spondyloarthritis and ERA in terms of etiology, genetics, pathogenesis and clinical manifestations summarized in this review, medications approved for axial SpA or peripheral SpA should also be studied in children with active ERA involving axial or peripheral joints, respectively, with the intent to achieve labeling for use in children. Considering the current lack of effective FDA-approved therapies for ERA, the FDA should also consider requiring pediatric studies for medications that have already been approved for the treatment of adults with SpA.</p>

<p>The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the American English language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability, and construct validity (convergent and discriminant validity). A total of 315 JIA patients (5.1% systemic, 31.1% oligoarticular, 34% RF negative polyarthritis, 29.8% other categories) and 98 healthy children, were enrolled in three centres. The JAMAR components discriminated well healthy subjects from JIA patients. All JAMAR components revealed good psychometric performances. In conclusion, the American English version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.</p>