[Juvenile dermatomyositis-what's new?]

Juvenile dermatomyositis (JDM) is the most common chronic inflammatory myopathy of childhood, which is still frequently characterized by a complicated disease course. In this review, novel findings relating to JDM are presented based on a review of the literature. Myositis-specific antibodies are often detected and may correlate with clinical phenotypes and disease course. Activation of type I interferon pathways plays an important pathogenic role and relates to the main clinical manifestations of the disease. This may lead to targeted therapies in the future. Currently, there are no treatments specifically approved for the treatment of JDM. Standard therapy is currently considered to include glucocorticoids and methotrexate based on a randomized controlled study and expert consensus. Several medications are commonly used in cases of refractory JDM, including azathioprine, ciclosporin, intravenous immune globulins, mycophenolate mofetil, and rituximab. An optimal treatment of JDM has not yet been established; however, there are national and international consensus recommendations and treatment plans that may aid in the decision-making process. Several validated tools are available to assess disease activity, disease damage, and treatment responses. Such tools should be routinely used in patients with JDM, and ideally be documented in registries in order to allow comparative effectiveness studies. The PRO-KIND initiative of the German Society for Pediatric Rheumatology has developed a diagnostic and a treat-to-target strategy based on a practice- and consensus-based process.