[Severe macrophage activation syndrome following visceral leishmaniasis in a child].

Visceral leishmaniasis (VL) is a parasitic disease that is a public health problem in Morocco and is one of the frequent infectious causes of macrophage activation syndrome (MAS). The combination of clinical and laboratory criteria, even very unspecific, make it possible to diagnose MAS, but a definitive diagnosis requires cytological examination. Rapid treatment is essential.