Hemophagocytic Lymphohistiocytosis (HLH) Definition: Overwhelming clinical syndrome associated with excessive macrophage activation and cytokine storm due to an underlying genetic immune dysfunction. It is rare in presentation, and most frequently affects infants < 3 months of age, however the disease is also observed in adults. Presentation / Diagnosis: HLH signs and symptoms can mimic common infections. It presents as an acute or subacute febrile illness associated with multiple organ involvement. Diagnosis via genetic testing for HLH-associated mutations OR 5 of the following: • Fever ≥38.5°C • Splenomegaly • Low or absent NK cell activity • Ferritin >500 ng/mL • Elevated soluble CD25 • Elevated CXCL9 • Hypertriglyceridemia • Hemophagocytosis in bone marrow, spleen, lymph node, or liver • Bicytopenia Treatment: • Infection should be diagnosed rapidly, and empiric antibiotic therapy should be initiated depending on the suspected organism • Supportive measures and treating the insulting agent are the main goal of therapy. If no response HLH-94-based therapy with etoposide and dexamethasone is indicated By @TheIDtrivia #HLH #Hemophagocytic #Lymphohistiocytosis #diagnosis #management #treatment #hematology
