Myopericarditis revealing adult-onset Still's disease

We report the case of a 33 year-old man presenting with fever, arthralgias, sore throat, dyspnea and chest pain. Myopericarditis was diagnosed on the basis of electrocardiogram, echocardiography and cardiac magnetic resonance imaging (MRI). The dramatic increase in ferritinemia suggested the diagnosis of adult-onset Still's disease (AOSD), which could be established according to criteria of Yamaguchi. Rapid improvement occured under corticosteroids. Myocarditis is very rare in AOSD, pericarditis being more frequent. We report herein the first description of AOSD associated myocarditis evidenced by cardiac MRI.