Clinical presentation of the idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIMs) are a group of disorders characterized by proximal muscle weakness and non-suppurative inflammation of skeletal muscle, often accompanied by extramuscular manifestations. The hallmark of the inflammatory myopathies is muscle weakness. Although this feature can lead to significant disability and impairment of activities of daily living, its initial presentation may not be recognized early. Pulmonary, gastrointestinal, or cardiac involvement, as well as underlying diseases, malignant or otherwise, may complicate the clinical picture. A focus on the clinical signs and symptoms, and directed laboratory tests, usually lead to the correct diagnosis and to proper assessment and treatment of the varied manifestations of the IIM.