[概念]多发性肌炎是Wagner在1863年首先描述,到1887年Unverricht认为本病常伴有皮肤症状,开始应用皮肌炎的名称,该二名称一直沿用至今.但有人指出多发性肌炎应该仅是一种狭义的名称,它仅是多发性肌炎综合症中之一种,多发性肌炎综合症的病因很多,可以由于感染、中毒、内分泌系统疾病、代谢、药物、胶原性疾病、癌肿等引起. [Concept] Polymyositis, first described by Wagner in 1863, was described by Unverricht in 1887 when dermatological symptoms were commonly associated with the disease and dermatomyositis was first introduced, and has been used since then. However, it has been suggested that polymyositis Should be just a narrow name, it is only one of polymyositis syndrome, polymyositis syndrome causes a lot, can be due to infection, poisoning, endocrine system diseases, metabolism, drugs, collagen disease , Cancer and other causes.