The document discusses three major types of inflammatory myopathies: polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM). PM is difficult to diagnose initially as symptoms develop gradually, while DM causes a characteristic rash that facilitates early detection. IBM primarily affects older patients and is often initially misdiagnosed as PM. DM is associated with increased risk of certain cancers but PM and IBM are not. Treatment options for inflammatory myopathies include glucocorticoids like prednisone and other immunosuppressive drugs, though IBM typically does not respond well to these therapies.