A sixteen-year-old girl presented with rash, elevated fever and joints swelling. She was admitted to the hospital to make further examinations as the symptoms persisted for 15 days. A diagnosis of probable Still disease was made. In the following days, her clinical state worsened, with persistence of elevated fever. Serologic tests were negative for Bartonella, Parvovirus B19, Rickettsia, viral hepatitis (A, B and C), HIV, Toxoplasma, Salmonella and Yersinia. Blood cultures were also negative. No abnormalities were found in abdominal and cardiac ultrasonography and in cranial computed tomography (CT). A bone gammagraphy, showed enhanced captation in right tibial malleolus and in proximal interphalangeal joints of fingers 2 and 4 of the right hand, and finger 4 of the left hand. An abdominal CT showed a biliary bladder wall enlargement and a laparotomy was performed, but no signs of cholecystitis were found. A broad spectrum antibiotherapy was started with ciprofloxacin and imipenem. The patient was transferred to pediatric intensive care unit (PICU) as a consequence of progressive multiorgan failure including acute respiratory distress syndrome, liver failure, anemia, thrombopenia and increasing acute phase reactants (APR). On admission to PICU, the patient was on mechanical ventilation. Examination revealed generalized oedema, hypoventilation in both lung bases, abdominal distension and hepatoesplenomegaly. There was also active bleeding around puncture points and through nasogastric tube. Blood analysis on admission is shown in table 1.