Idiopathic inflammatory myopathy

Idiopathic inflammatory myopathies (IIM) are a group of acquired immune myopathy, which mainly include polymyositis, dermatomyositis, amyopathic dermatomyositis, sporadic inclusion body myosistis (sIBM) and immune-mediated necrotizing myopathy, as well as some special types of antisynthetase syndrome, anti-signal recognition particle antibody positive necrotizing myopathy (NM), anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody positive NM. The diagnosis of these different types of IIM mainly depends on clinical manifestations, antibody detection and muscle pathological techniques. Different types of IIM have different clinical manifestations, or overlapping manifestations. This article systematically describes the evolution of IIM types, the main antibodies to myositis, the pathological characteristics of muscles, the manifestations of various types and the treatment of myositis. In addition to sIBM, patients with most of the other types of IIM have good outcomes by early diagnosis, timely, correct and adequate drug treatment. Key words: Idiopathic inflammatory myopathies; Polymyositis; Dermatomyositis; Sporadic inclusion body myosistis; Immune-mediated necrotizing myopathy