Amyopathic dermatomyositis with a rapidly progressing interstitial pneumonia

Anti-melanoma differentiation-associated protein 5 (anti-MDA5) associated clinically amyopathic dermatomyositis (CADM) is an extremely rare disease associated with significantly higher morbidity and mortality compared to other inflammatory myopathies.This report describes a unique case of a patient who presented with an acute interstitial pneumonia and rapidly progressing respiratory failure due to an undiagnosed anti-MDA5 amyopathic dermatomyositis, without any of the typical dermatomyositis symptoms or physical exam findings.Diagnosis of anti-MDA5 amyopathic dermatomyositis is challenging and standardized treatments for this disease have not been fully developed, which highlights the importance of multidisciplinary approach and collaboration between medical centres.