Hemophagocytic Lymphohistiocytosis Associated With Epstein-Barr Virus Infection in an Immunocompetent Adult.

Hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal entity characterized by an unregulated activation of the immune system. In the adult population, it is most commonly secondary to infectious, autoimmune, or neoplastic diseases. We present a case of a 23-year-old female diagnosed with infectious mononucleosis and hospitalized due to a persistent three-week fever and malaise with a new onset of jaundice and findings compatible with acute hepatitis and hepatosplenomegaly. Due to a lack of response to standard supportive care, maintained fever, persistent analytical worsening (hyperferritinemia, bicytopenia, cytocholestasis, and hypertriglyceridemia), and hemophagocytocic phenomena on myelogram, the diagnosis of HLH secondary to Epstein-Barr virus infection was attained. Treatment with systemic corticosteroids was initiated with a continuously favorable evolution. This case aimed to describe and highlight the complexity of the diagnostic approach and the urgency of directed therapeutic attitudes in the management of HLH.