Prompt Recognition of Hemophagocytic Lymphohistiocytosis in an Afebrile Patient with Lupus and Staphylococcus aureus Bacteremia.

BACKGROUND Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by dysregulated immune system activation and hyperinflammation. Primary HLH is inherited and almost exclusively seen in childhood, while secondary HLH is mainly seen in adults and has a wide variety of triggering factors, including infection, malignancy, autoimmune disease, and immunosuppression. Due to nonspecific presentation, the differential diagnosis for HLH is equally wide.

Hemophagocytic lymphohistiocytosis in systemic mastocytosis treated with allogeneic bone marrow transplant: A case report.

Systemic mastocytosis is a rare entity in pediatrics, usually associated with mutations in the c-KIT gene. We describe a Caucasian female who presented with severe systemic mastocytosis with food allergies requiring prolonged total parenteral nutrition. Her course was further complicated by the onset of hemophagocytic lymphohistiocytosis, which responded poorly to conventional chemotherapy.