Adult-onset Still's disease presenting as myopericarditis.

A 24-year-old man presented to the emergency department with fever, maculopapular rash, myalgia and polyarthralgia, thoracic pain and dry cough, which had been present for 24 h. At the time of observation he had high fever (39°C), maculopapular rash on the torso, arms and legs proximally, axillary adenopathies and pharyngitis. Laboratorial data showed elevated inflammation markers (leukocytosis, C reactive protein of 44 mg/dL, erythrocyte sedimentation rate of 120 mm), elevated transaminases, lactate dehydrogenase, ferritin levels (>2000 ng/mL) and rising troponin. ECG had sinus rhythm and ST elevation in leads V1-V5. Thoracic radiography revealed bilateral interstitial infiltrate confirmed by CT scan. Echocardiographic findings included diffuse hypokinesia of the left ventricle and impaired systolic function. After the investigation of an infectious or autoimmune aetiology was negative, the diagnosis of adult-onset Still's disease was considered. The patient was put on a 60 mg/day prednisolone regimen with remission of symptoms and normalisation of systolic function and ECG.