Hemorrhagic shock and encephalopathy syndrome (HSES) is a type of acute encephalopathy mainly seen in infants. It is a syndrome encompassing an onset of high fever, disturbance of consciousness, convulsion, and shock that rapidly progresses to watery diarrhea and liver and renal dysfunctions. It is extremely rare in adults, and the number of reports is limited worldwide. We report the case of an adult patient with HSES, which occurred after influenza A infection.A 52-year-old man visited his family doctor 2 days after he noticed fever and was diagnosed with influenza A using an influenza rapid diagnosis kit; he underwent treatment on an outpatient basis. He was immediately hospitalized after developing fever, abdominal pain, malaise, and shock 16 hours after the commencement of the treatment. Abrupt acute brain swelling was noted 24 hours after hospitalization.The antibody titer to influenza A (H3N2) was 1:40. Computed tomography obtained 24 hours after treatment initiation confirmed acute cerebral edema and cerebral herniation. Electroencephalogram at that time showed a flat line.For the treatment of influenza A, laninamivir 150 mg was started immediately after the diagnosis by the family doctor, and 600 mg dose was given daily after hospitalization (or since 24 hours after the treatment initiation). For the management of shock, dobutamine 3 μg/kg/min and noradrenaline up to 0.2 μg/kg/min were used together with bolus infusion.The patient was declared brain dead on his 6th hospital day and he died on his 27th hospital day.Drastic courses such as that in our case with HSES can follow influenza infections even in adults.
