Epstein-Barr virus (EBV) is associated with hypersensitivity to mosquito bites (HMB) and fatal EBV-associated hemophagocytic syndrome (HPS). The prognosis of patients with chronic active EBV infection (CAEBV) is very poor. We report a rare case of an adult woman patient with a 28-yr history of HMB, who developed EBV-HPS. EBV genome was detected in the serum and peripheral blood lymphocytes. Clonal proliferation of EBV was demonstrated by Southern blot analysis using an EBV genome terminal-repeat probe. This is a very rare case of a long-term survivor with CAEBV. The patient was initially treated with immunochemotherapy and achieved complete remission. However, the patient immediately relapsed and underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched brother. Peripheral blood cell recovered well, and EBV genome disappeared from the peripheral blood. Allogeneic BMT may be effective in eradicating EBV-HPS. Unfortunately, the patient died of graft vs. host disease on the 92nd day after BMT.