[Histiocyte activation syndrome associated with EBV in children].

VAHS (virus associated hemophagocytic syndrome) is a severe clinical and biological condition associated with certain menacing viral infections. It has been observed in patients with manifest immunodeficiency but also in previously apparently healthy children. Epstein-Barr virus (EBV) infection, although it is sometimes unrecognized and insidious, is one of the etiologies to be considered. Differential diagnosis with other causes of macrophage activation is a delicate task in pediatrics. Better understanding of the pathophysiology of the syndrome offers interesting therapeutic prospects.