RT Journal Article SR Electronic T1 Idiopathic inflammatory myopathies – a guide to subtypes, diagnostic approach and treatment JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 322 OP 328 DO 10.7861/clinmedicine.17-4-322 VO 17 IS 4 A1 Alexander Oldroyd A1 James Lilleker A1 Hector Chinoy YR 2017 UL http://www.rcpjournals.org/content/17/4/322.abstract AB The idiopathic inflammatory myopathies are a group of conditions characterised by inflammation of muscles (myositis) and other body systems. The diagnosis can be challenging because of the many potential clinical features and extra-muscular manifestations, which may be seemingly unrelated. An accurate diagnosis requires up-to-date understanding of the clinical manifestations, different clinical subtypes and appropriate interpretation of investigations, including newly described serological subtypes.This review will detail the approach to the diagnosis of an idiopathic inflammatory myopathy, based on up-to-date knowledge. The recently updated classification criteria and treatment options will also be described.