Idiopathic Inflammatory Myositis

Idiopathic inflammatory myopathies are a heterogeneous group of chronic autoimmune disorders that mainly affect the proximal muscles. The most common types include dermatomyositis (DM), polymyositis (PM), immune-mediated necrotizing myopathy (IMNM), and sporadic inclusion body myositis (sIBM). Patients typically present with progressive, proximal weakness and functional impairment. Extramuscular manifestations may also be present. Laboratory investigations with raised serum creatine kinase (CK) and myositis-specific antibodies (MSA) may help in diagnosis, differentiating the clinical phenotype and confirming the myositis subtype. The major goals of treatment are to eliminate inflammation, restore muscle performance, reduce mortality, and improve quality of life.