The idiopathic inflammatory myopathies (IIM) dermatomyositis (DM) and polymyositis (PM) are chronic diseases affecting the striated muscles with variable involvement of other organs. Glucocorticoids are considered the cornerstone of treatment, but some patients require adjunctive immunosuppressive agents because of insufficient response to glucocorticoids, flares upon glucocorticoid tapering, or glucocorticoid-related adverse events. Areas covered: The aim of this article was to review (PubMed search until February 2018) the evidence on established and new therapies derived from randomized controlled trials (RCTs) on adult DM and PM. In addition, key data from open-label trials, case reports, and abstracts were included where data from RCT were lacking. Expert commentary: Numerous synthetic and biological immunosuppressive agents are currently available to treat the IIM, sometimes in combination. The choice of the specific medication in the individual patient depends upon the disease phenotype and patient's characteristics. Exercise improves muscle performance without causing disease flares and should be an integral part of the treatment of the IIM. Prompt diagnosis and treatment can lead to better outcome.
Keywords: Biological agents; dermatomyositis; disease-modifying anti-rheumatic drugs; glucocorticoids; myositis; polymyositis.