Idiopathic Inflammatory Myositis

IIMs are autoimmune disorders that can affect all ages and are characterized by a spectrum of clinical manifestations, the most common of which is skeletal muscle weakness. Several MSAs have been identified and may help to inform treatment and direct the evaluation for extramuscular features. As a multisystemic disorder, a thoughtful approach taking into consideration clinical, serologic, and histologic data is required to develop a patient-specific management strategy. Treatment remains suboptimal in many cases and, owing to the rarity of these disorders, is based primarily on small series because there a few randomized controlled trials to inform management of IIMs.