Inflammatory myopathies in children

Juvenile idiopathic inflammatory myopathies (JIIM) are rare conditions that are probably autoimmune in nature. Childhood myositis is relatively more homogeneous than adult myositis; juvenile dermatomyositis (JDM) is by far the most common inflammatory myopathy, followed by far fewer cases of juvenile polymyositis, amyopathic dermatomyositis, overlap myositis, and inclusion body myositis. Childhood myositis differs also in the higher incidence of vasculopathy, often with intimal proliferation of small blood vessels, thrombosis, and sometimes infarction [1,2]. Although JDM is the most common presentation (with primarily skin and muscle manifestations), the underlying systemic vasculopathy can involve many systems. Treatment is directed toward reducing inflammation through immunosuppression. The disorders have a good outcome with favorable prospects for normal school and work performance, but many of the affected children will have a chronic disease and will require longterm therapy. This article describes a recent patient who presented with typical JDM and uses her case to discuss aspects of the childhood inflammatory myopathies.