Emergency admission with unremitting fever and lymphadenopathy: Kikuchi-Fujimoto disease causing haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis (HLH) is a severe systemic inflammatory syndrome. Over activation of histiocytes and lymphocytes can lead to multiorgan failure and death. The three key features are fever, raised ferritin and falling counts, that is, cytopenia (3Fs). Treatment is immunosuppression while identifying the driver. Our young female patient presented with high fever and extensive lymphadenopathy, raising the suspicion of HLH driven by lymphoma. Her H-score was consistent with HLH. Immunosuppression was commenced with intravenous steroids, followed by anakinra due to inadequate steroid response. She required intensive care unit (ICU) admission with input from haematology and rheumatology. A lymph node biopsy revealed likely Kikuchi-Fujimoto disease, a rare benign cause of painful lymphadenopathy that is usually self-limiting but is also reported as a cause of HLH. She responded rapidly to anakinra and was discharged home 1 week after leaving ICU. Regular clinic follow-up continues, immunosuppression has been weaned off and she remains in remission. Monitoring for later development of autoimmune disease continues. We discuss her management with reference to the recently published Getting it Right First Time guidelines on HLH.