SECONDARY HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS IN A CHILD WITH CONCOMITANT EBSTEIN BARR VIRUS AND SCRUB TYPHUS INFECTION – A RARE ENTITY

Abstract

Scrub typhus is a life threatening zoonosis caused by Orientia tsutsugamushi organisms that are transmitted by the larvae of trombiculid mites. It is endemic to a geographically distinct region, the so called Tsutsugamushi triangle, which includes Japan, China and South Korea. The disease is more prevalent in southern and northern India.It is characterised by focal or disseminated vasculitis and perivasculitis involving the lungs, liver, spleen and central nervous system. We report our experience with pediatric scrub typhus at a hospital in eastern India with EBV positive and secondary HLH. An 8 year old boy with fever, maculopapular rash, hepatosplenomegaly and lymphadenopathy was admitted in our institution and diagnosed with Scrub typhus. Physical and laboratory data showed hepatosplenomegaly, bicytopenia, hyperferritinemia, and hypobrinogenemia. Secondary HLH was diagnosed and the child was managed with IVIG and steroids. In view of rash followed by lymphadenopathy and hepatosplenomegaly EBV serology was also sent as a cause of HLH. Surprisingly, EBV panel was also positive. We therefore concluded that the most probable explanation was EBV triggered HPS following scrub typhus infection. Another possible explanation is EBV can be reactivated in critically ill patients. To our knowledge this is the rst such case in the pediatric population reported till date.