Résumé
An 11-year-old girl presented with a typical serologically proven infectious mononucleosis with persistent fever, jaundice and hepatosplenomegaly in spite of steroid therapy. Laboratory tests showed pancytopenia, fibrinopenia and hypertriglyceridemia. The liver biopsy revealed an infiltration with hyperbasophilic cells. One month later, a slight improvement was noted and fever disappeared after 4 days on acyclovir therapy. The authors recall the spectrum of the macrophagic activation syndrome.An 11-year-old girl presented with a typical serologically proven infectious mononucleosis with persistent fever, jaundice and hepatosplenomegaly in spite of steroid therapy. Laboratory tests showed pancytopenia, fibrinopenia and hypertriglyceridemia. The liver biopsy revealed an infiltration with hyperbasophilic cells. One month later, a slight improvement was noted and fever disappeared after 4 days on acyclovir therapy. The authors recall the spectrum of the macrophagic activation syndrome.