Hemophagocytic Lymphohistiocytosis (HLH)

• HLH is a hematologic disorder that results from overactivation of the immune response (macrophages and cytotoxic T cells).
• HLH is often underrecognized and has a mortality that can be as high as 75%.
• Secondary HLH is most commonly associated with infection (sepsis), malignancy (lymphoma), and autoimmune disorders (SLE, RA).
• Hallmark features of HLH include fever, splenomegaly, hepatomegaly, cytopenias, coagulopathy, elevated ferritin, elevated triglycerides, and decreased fibrinogen levels.
• ED resuscitation of patients with suspected HLH includes Hematology consultation, treatment of the underlying disorder (infection), and potentially corticosteroids and chemotherapeutic agents.

References

Morrissette K, et al. Hemophagocytic lymphohistiocytosis in the emergency department: recognizing and evaluating a hidden threat. J Emerg Med. 2021;60:743-751.