Inflammatory myopathies are the potentially treatable group of disorders (dermatomyositis, polymyositis,
and inclusion-body myositis) classified on the basis of distinct clinic-pathologic features.
However, the identification of the correct subtype is fundamental, because each subtype has a different
prognosis and response to therapies. This review reflects the current knowledge of the correct
diagnosis of subtype, describes the main clinicopathologic and immunologic features, and provides
practical guidelines regarding therapies.