Key Takeaways

✅ Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder of excessive inflammation. It should be suspected in patients who present with fever, cytopenias, and evidence of multiple organ involvement.

✅ No clinical, laboratory, or histopathologic finding alone is pathognomonic for the diagnosis of HLH.

✅ HLH is either primary (caused by genetic mutations in NK or T cell function) or secondary (driven by infection, malignancy, or autoimmune disease).

✅ The work-up of HLH should include identifying complications of systemic inflammation as well as a search for a underlying trigger/cause.

✅ The hallmark of HLH treatment is immunosuppression with corticosteroids and etoposide. Additional treatment should be directed at the underlying cause, if isolated.