Hemophagocytic lymphohistiocytosis in newborn and infants

Familial hemophagocytic lymphohistiocytosis (FHL or HLH) is a rare disorder of early infancy with autosomal recessive inheritance and usually fatal outcome. Its frequency has been estimated around 1 in 50.000 children/year in Sweden. The disease was initially reported in 1952 by a pediatrician who already described most of its prominent features, i.e. propensity to fatal outcome following an infectious disease, a lymphoma-like picture, peculiar observation of hypertriglyceridemia and hemophagocytosis. The familial recurrence of this disease clearly pointed to a genetic defect.