Autoimmune Myopathies.

PURPOSE OF REVIEW: This article provides guidelines for diagnosing and treating the different subtypes of autoimmune myopathies.

RECENT FINDINGS: The most common subtypes of autoimmune myopathies are dermatomyositis, immune-mediated necrotizing myopathy, antisynthetase syndrome, and overlap syndromes; isolated polymyositis is an exceptionally rare disease. Specific autoantibodies are associated with unique clinical phenotypes and may be used for diagnostic and prognostic purposes, such as to assess the risk of coexisting malignancy.

SUMMARY: Diagnosing the specific subtype of autoimmune myopathy can be achieved by combining relevant features of the history, neuromuscular examination, muscle biopsy, and serologic studies.