Successful treatment with intravenous high‐dose immunoglobulin for cardiomyopathy in dermatomyositis complicated with rapid progressive interstitial pneumonia

Cardiomyopathy and rapid progressive interstitial pneumonia ( IP ) are potentially fatal complications in polymyositis/dermatomyositis. We experienced a dermatomyositis patient with multiple adverse prognostic factors, complicating rapid progressive IP , macrophage activation syndrome ( MAS ), and cardiomyopathy. IP and MAS improved with strong immunosuppressive therapy, despite which cardiomyopathy developed. Therefore, we applied intravenous high‐dose immunoglobulin therapy ( IVI g), and cardiac function improved dramatically. This is the first report to present the effectiveness of IVI g for cardiomyopathy in dermatomyositis.