Hemophagocytic lymphohistiocytosis in the premature neonate.

Hemophagocytic lymphohistiocytosis (HLH), a rare disease, results in pathological findings secondary to an abnormal proliferation of activated lymphocytes and histiocytes (tissue macrophages) and is lethal unless identified and adequately treated. Clinical features of HLH include fever, hepatosplenomegaly, cytopenias, hypertriglyceridemia, hypofibrinogenemia, elevated blood levels of ferritin, lymphadenopathy, skin rash, jaundice, and edema. Often, the symptoms of HLH are misinterpreted as infection, resulting in inadequate treatment and death. Several case studies of premature neonates with HLH have recently been published. Therapeutic guidelines for HLH exist and, when identified, HLH in the premature infant can be successfully treated resulting in resolution of symptoms.