Department of Neurology, Dell Medical School, University of Texas, Austin, Texas.
Semin Neurol. 2020 Jun;40(3):342-348. doi: 10.1055/s-0040-1705120. Epub 2020 Apr 6.
The inflammatory myopathies comprise disorders of immune-mediated muscle injury. The histopathology and clinical features help distinguish them. Juvenile dermatomyositis (JDM) is the most common form of myositis in children and adolescents. Children with JDM present with proximal muscle weakness and characteristic rashes. The presentation is similar in children and adults, but JDM is a primary disorder and the adult form often is concerning for a paraneoplastic syndrome. Proximal muscle weakness occurs with dermatomyositis, polymyositis, and immune-mediated necrotizing myopathy, but the latter two conditions have no dermatologic findings or distinct tissue changes which set them apart from dermatomyositis. Inclusion body myositis, also included in the inflammatory myopathies, presents with more distal involvement, and microscopically exhibits identifiable rimmed vacuoles. We review key features of these disorders, focusing in more detail on JDM because it is more often encountered by the child neurologist.
炎症性肌病包括免疫介导的肌肉损伤疾病。组织病理学和临床特征有助于对其进行鉴别。幼年特发性皮肌炎（juvenile dermatomyositis，JDM）是儿童和青少年中最常见的肌炎类型。患有 JDM 的儿童会出现近端肌无力和特征性皮疹。儿童和成人的表现相似，但 JDM 是原发性疾病，而成人型通常与副肿瘤综合征有关。近端肌无力可见于皮肌炎、多发性肌炎和免疫介导性坏死性肌病，但后两者没有皮肤表现或明显的组织改变，这将它们与皮肌炎区分开来。包涵体肌炎也属于炎症性肌病，其特点是远端受累更明显，显微镜下可见可识别的边缘空泡。我们将回顾这些疾病的关键特征，并更详细地介绍 JDM，因为儿童神经病学家更常遇到这种疾病。
