Acute respiratory distress syndrome relapsing in 10 months with an initial manifestation of polymyositis

Autoimmune disorders are an important cause of acute respiratory distress syndrome (ARDS). We report a case of a patient with steroid‐responsive ARDS that relapsed in 10 months with an initial manifestation of seronegative polymyositis. ARDS associated with polymyositis may develop earlier than myopathy and may relapse later. The differential diagnosis of acute respiratory distress syndrome without clear etiology should include a pulmonary manifestation of polymyositis and dermatomyositis, which may develop earlier than myopathy and may relapse later.