RESUMO
Epstein-Barr virus (EBV) infection results in a spectrum of clinical manifestations. The host immune response to EBV plays a key role in the extent and degree of clinical features, which in children under 4 years of age are usually mild, non-specific and self-limiting. A 2-year-old boy in whom no known immune disorder could be found presented with acute acalculous cholecystitis, renal dysfunction with massive proteinuria, ascites, pleural effusion, minimal peripheral oedema and a severe systemic inflammatory response. Improvement occurred after initiation of corticosteroids and antiviral treatment with gancyclovir. In severely symptomatic or complicated EBV infection, a primary immunodeficiency must be suspected. If a primary immunodeficiency has been ruled out, the correct management of severe EBV infection in the immunocompetent host remains controversial.