Introduction: Adult-onset Still disease can have severe manifestations, the treatment of which is not yet codified.
Case: The authors report a case of life-threatening adult-onset Still disease with hemophagocytic syndrome, which improved dramatically with cyclosporin A. Despite the presence of severe pancytopenia, adult-onset Still disease is suggested by the combination of sore throat, myalgia, rash, hepatitis, high serum ferritin, low glycosylated ferritin, and negative etiologic findings.
Discussion: Still disease may be present in patients with febrile pancytopenia, and cyclosporine may be a useful treatment after corticosteroid failure.