Extra-muscular complications affecting patients suffering from the idiopathic inflammatory myopathies (IIM) are common, and appear in recognizable patterns affecting the skin, lungs, joints, oesophagus or heart, although these complications rarely all occur simultaneously. During the initial presentation of symptoms, involvement of organs other than muscle can aid the confirmation of the correct IIM subtype. Extra-muscular manifestations can be severe and life-threatening, e.g. with respiratory or cardiac involvement. Escalations of immunosuppression and other treatment modalities will likely be required in such cases since standard immunosuppression usually is not sufficient for an effective treatment of e.g. interstitial lung disease. IIM patients should therefore be regularly checked for extra-muscular manifestations, and management altered as appropriate.
Cardiac involvement in adult and juvenile idiopathic inflammatory myopathies