Calcinosis is one of the hallmark sequelae of juvenile dermatomyositis (JDM), and despite recent progress in the therapy of JDM, dystrophic calcification still occurs in approximately one-third of patients. This review discusses our current, albeit limited, understanding of risk factors for the development of calcinosis in JDM, as well as approaches to assessment, and current views on its pathogenesis. Anecdotal approaches to treating calcinosis associated with JDM, including both anti-inflammatory therapies and agents aimed at inhibiting the deposition of calcium hydroxyapatite, are reviewed. An improved understanding of the pathogenesis of calcinosis, the establishment of standardized measurement tools to assess calcinosis, and randomized controlled trials employing more sensitive outcome measures are needed to develop efficacious therapies for this often disabling complication.

A novel B-Mode and Doppler image acquisition and scoring system for assessing synovitis in the pediatric knee was successfully developed through practical exercises and consensus process. Study results demonstrate overall good to excellent reliability. This article is protected by copyright. All rights reserved.

BackgroundJuvenile dermatomyositis (JDM) is the most common form of the idiopathic inflammatory myopathies in children. A subset of children have the rash of JDM without significant weakness, and the optimal treatments for these children are unknown. The goal of this study was to describe the development of consensus clinical treatment plans (CTPs) for children with JDM who have active skin rashes, without significant muscle involvement, referred to as skin predominant JDM in this manuscript.MethodsThe Children’s Arthritis and Rheumatology Research Alliance (CARRA) is a North American consortium of pediatric rheumatology health care providers. CARRA members collaborated to determine consensus on typical treatments for JDM patients with skin findings without significant weakness, to develop CTPs for this subgroup of patients. We used a combination of Delphi surveys and nominal group consensus meetings to develop these CTPs.ResultsConsensus was reached on patient characteristics and outcome assessment, and CTPs were developed and finalized for patients with skin predominant JDM. Treatment option A included hydroxychloroquine alone, Treatment option B included hydroxychloroquine and methotrexate, and Treatment option C included hydroxychloroquine, methotrexate and corticosteroids.ConclusionsThree CTPs were developed for use in children with skin predominant JDM, which reflect typical treatment approaches. These are not considered to be specific recommendations or standard of care. Using the CARRA network and prospective data collection, we will be able to apply statistical methods in the future to allow comparisons of JDM patients following these consensus treatment plans.

Objective Magnetic resonance imaging (MRI) is pivotal in the assessment of early sacroiliitis in children. We aimed to evaluate the agreement between local radiology reports and central imaging reviewers for active inflammation and structural damage at the sacroiliac (SI) joints. Methods Eight hospitals each contributed up to 20 cases of consecutively imaged children and adolescents with juvenile idiopathic arthritis and suspected sacroiliitis. Studies were independently reviewed by 3 experienced musculoskeletal pediatric radiologists. Local assessments of global impression and lesions were coded from the local radiology reports by 2 study team members. Test properties of local reports were calculated using the central imaging team’s majority as the reference standard. Results For 120 evaluable subjects, the median age was 14 years, half of the cases were male, and median disease duration at the time of imaging was 0.8 years (interquartile range 0–2). Sensitivity of local reports for inflammation was high, 93.5% (95% confidence interval [95% CI] 78.6–99.2), and specificity was moderate, 69.7% (95% CI 59.0–79.0), but positive predictive value (PPV) was low, 51.8% (95% CI 38.0–65.3). Twenty‐seven cases (23%) had active inflammation reported locally but rated normal at the central reading, 19 (70%) with subsequent medication changes. The sensitivity of local reports detecting structural damage was low, 45.7% (95% CI 28.8–63.4), and specificity was high, 88.2% (95% CI 79.4–94.2); PPV was low, 61.5% (95% CI 40.6–79.8). Conclusion Substantial variation exists in the interpretation of inflammatory and structural lesions at the SI joints in children. To reliably identify pathology, additional training in the MRI appearance of the maturing SI joint is greatly needed.

These data suggest that truly amyopathic JDM is rare and that a thorough workup that includes all five muscle enzymes and MRI may uncover occult myositis.

Objective. To develop and initially validate a comprehensive pediatric musculoskeletal ultrasound (MSUS) joint-specific scoring system, and to determine the minimum number of joints needed to identify active disease.Methods. A semiquantitative scoring system was developed by consensus and initially validated by interrater reliability using intraclass correlation coefficients (ICCs). Subsequently, newly diagnosed juvenile idiopathic arthritis patients with an active joint count of >4 had a 42-joint MSUS performed at baseline and 3 months using this protocol. A minimum set of joints needed to identify all patients with synovitis on MSUS was obtained through a data reduction process. Spearman's correlation (r s ) was calculated to determine the association between MSUS findings and clinical Juvenile Arthritis Disease Activity Score in 10 joints (cJADAS10). Standardized response means (SMRs) were used to assess change over time.Results. The final joint-specific scoring system revealed an excellent interrater reliability (ICC 0.81-0.96) for all joints. Thirty patients were enrolled. Scanning 5 joints bilaterally (wrists, second and third metacarpophalangeal joints, knees and ankles) captured 100% of children with B-mode synovitis and had moderate correlation with the cJADAS10 at baseline (r s = 0.45). Mean ultrasound scores at baseline and follow-up were 28.3 and 22.3, with an SRM of 0.69 (P = 0.002) for 42 joints, and 36 and 27.7, with an SRM of 0.76 (P = 0.003) for the reduced joints, respectively.Conclusion. A limited MSUS examination called musculoskeletal ultrasound in childhood arthritis limited examination (MUSICAL) captures all patients with active synovitis, and our new joint-specific scoring system is highly reliable and sensitive to change.

Juvenile idiopathic arthritis (JIA) is a group of disorders characterized by arthritis persisting for at least 6 weeks with onset before the age of 16 years. Within this cluster of conditions, the polyarticular form (involving more than four joints within the first 6 months) is further divided based on the presence of rheumatoid factor. Children with polyarticular JIA pose unique diagnostic and therapeutic challenges compared to children with involvement of fewer joints. Polyarticular JIA patients tend to have a more refractory course and therefore are at increased risk for joint damage, resulting in poorer functional outcomes and decreased quality of life. Although the ability to treat this disorder continues to improve, especially with the advent of biologic agents, there is still much about the epidemiology and pathogenesis of polyarticular JIA that is unknown. The epidemiology of polyarticular JIA varies worldwide with a vast difference in reported cases between different global regions as well as within individual countries. Several genetic risk loci have been identified conferring increased susceptibility to JIA, many within the human leukocyte antigen region. Beyond the genome, environmental factors also seem to contribute to the etiology of polyarticular JIA. This review article will focus on the epidemiology and current treatments of polyarticular JIA and briefly discuss genetic and environmental influences on the pathogenesis of JIA as well as new and emerging therapies.

Objective The goal was to characterize short‐term kidney status and describe variation in early care utilization in a multicenter cohort of patients with childhood‐onset systemic lupus erythematosus (cSLE) and nephritis. Methods We analyzed previously collected prospective data from North American patients with cSLE with kidney biopsy‐proven nephritis enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry from March 2017 through December 2019. We determined the proportion of patients with abnormal kidney status at the most recent registry visit and applied generalized linear mixed models to identify associated factors. We also calculated frequency of medication use, both during induction and ever recorded. Results We identified 222 patients with kidney biopsy–proven nephritis, with 64% class III/IV nephritis on initial biopsy. At the most recent registry visit at median (interquartile range) of 17 (8–29) months from initial kidney biopsy, 58 of 106 patients (55%) with available data had abnormal kidney status. This finding was associated with male sex (odds ratio [OR] 3.88, 95% confidence interval [95% CI] 1.21–12.46) and age at cSLE diagnosis (OR 1.23, 95% CI 1.01–1.49). Patients with class IV nephritis were more likely than class III to receive cyclophosphamide and rituximab during induction. There was substantial variation in mycophenolate, cyclophosphamide, and rituximab ever use patterns across rheumatology centers. Conclusion In this cohort with predominately class III/IV nephritis, male sex and older age at cSLE diagnosis were associated with abnormal short‐term kidney status. We also observed substantial variation in contemporary medication use for pediatric lupus nephritis between pediatric rheumatology centers. Additional studies are needed to better understand the impact of this variation on long‐term kidney outcomes.