Atypical presentation of adult Still's disease mimicking acute bacterial endocarditis

Adult Still's disease is a chronic, systemic disease of unknown origin. We describe the case of an otherwise healthy man with an uncommon presentation of Still's disease. A 38-year-old man presented with sore throat, fever, rash and arthritis. Laboratory findings showed that both erythrocyte sedimentation rate and ferritin had increased. Transoesophageal echocardiography revealed a vegetation involving the aortic leaflet. The diagnosis of Still's disease was made after the exclusion of infectious endocarditis, based upon the clinical picture, the high level of ferritin and the follow-up. The patient markedly improved after treatment with prednisone 1 mg. kg-1. This controlled and then progressively reduced the disease; the drug was then withdrawn. This case illustrates that Still's disease can present with endocardial involvement mimicking acute bacterial endocarditis as a first clinical manifestation. The observation suggests that the presence of high ferritinaemia in a patient with some clinical criteria of Still's disease could lead to an early diagnosis.