[Dermatomyositis].

Dermatomyositis (DM) is distinguished from other idiopathic inflammatory myopathies by the characteristic skin rashes, muscle pathology, and muscle symptoms. Five myositis-specific autoantibodies have been identified in DM, and the correlation between each antibody and the clinical picture is clear. Pathological analysis has also identified DM as a type I interferonopathy of the skeletal muscle. Consideration of treatment strategies requires careful evaluation of muscle strength, systemic inflammatory findings, muscle pathology, muscle imaging, and complications such as malignancy and interstitial lung disease. Corticosteroids are administered as first-line treatment, and immunosuppressive agents and intravenous immunoglobulins are employed as important second-line treatments. Some patients exhibit resistance to these therapies. Currently, treatment strategies for refractory cases are not well established, necessitating further development of treatment methods.