Paediatrics: Haemophagocytic lymphohistiocytosis

Haemophagocytic lymphohistiocytosis

A rare condition that may be p (familial haemophagocytic/eryth-rophagocytic lymphohistiocytosis, FHL or FEL) or s to infection (sHLH). Characterized by accumulation of phagocytic mononuclear cells, rather than dendritic or antigen-presenting cells as seen in LCH.

·Presenting features: include fever, splenomegaly, and cytopenia (2 out of 3 cell lines—red cells, white cells, and platelets). Neurological symptoms relating to increased CSF cell counts and protein sometimes seen. There may also be lymphadenopathy, skin rash, jaundice and oedema, and hepatic dysfunction.

·Biochemistry: shows raised triglycerides and low fibrinogen, sometimes raised serum transaminases and ferritin levels.

·Other investigations to consider: include viral, immunological, and genetic testing.

Treatment

Recovery may be spontaneous in sHLH with resolution of infection, but FHL is fatal without treatment. Steroids, etoposide, IT methotrexate may stabilize the disease. Allogeneic BMT is required for cure. Overall survival is 750%.