Adult onset Still's disease as a cause of ARDS and acute respiratory failure.

We report a case of a young woman with pyrexia and progressive lung disease who developed acute respiratory distress syndrome (ARDS) and required prolonged mechanical ventilator support. The patient had a markedly elevated serum ferritin concentration of 7880 micrograms/L, a specific finding for the adult onset Still's disease (AOSD). Treatment of the patient with supportive and immunosuppressive therapy, resulted in patient survival and cure. The early consideration of the diagnosis of AOSD in patients with fever of unknown origin and a compatible clinical course may modify its severe complications.