Idiopathic inflammatory myopathies-a review.

The idiopathic inflammatory myopathies (IIM) constitute a subset of autoimmune conditions primarily affecting muscle, along with many extra-muscular manifestations. Proximal muscle weakness is the dominant symptom in the IIM. In addition, many patients will have cutaneous manifestations, pulmonary manifestations, and arthritis. There is an increased incidence of malignancy with the IIM. Diagnostic tools beyond history and physical exam include serum muscle enzyme and autoantibody testing, magnetic resonance imaging (MRI) of the extremities, ultrasound, neurologic testing, and muscle biopsy. Several options for treatment are reviewed.