Pulmonary manifestations of polymyositis/dermatomyositis

Both polymyositis (PM) and dermatomyositis (DM) are primary, autoimmune-mediated, skeletal muscle diseases. This aberrant immune response to skeletal muscle is also associated with diffuse systemic pathology. Pulmonary vascular and parenchymal inflammation as well as thoracic musculoskeletal weakness is less prominent in frequency studies regarding the varied morbidity of PM/DM. However, lung involvement in general is associated with a more moribund disease course. Epidemiologic studies have improved our understanding of the frequency and prognostic impact of many of these complications. With this understanding comes a growing appreciation of the pathophysiology of PM/DM and the lung, and how a clinician may prevent or potentially address these adverse effects.