Abstract
Haemophagocytic lymphohistiocytosis (HLH) describes a rare, poorly recognised and under-diagnosed immunopathological syndrome whereby there is a highly stimulated yet ineffective multisystem inflammatory response [1]. I present the first case in English literature of Cytomegalovirus (CMV) associated HLH diagnosed by clinical and serological means, and the fourth case of CMV associated haemophagocytic lymphohistiocytosis in an immunocompetent adult, according to HLH-2004 diagnostic guidelines. I include a literature review of CMV associated HLH in adults and raise awareness of checking serum ferritin in patients who present with a sepsis like syndrome. Additionally, this article discusses the merits of HLH-2004 diagnostic work-up without bone marrow biopsy, using clinical and serological means only. I support the reclassification of HLH alongside the other hyperinflammatory syndromes of SIRS, sepsis, septic shock, and MODS to improve understanding and recognition.