The child with prolonged fever: when to think zebras

Everyone remembers the adage beloved of medical school professors ‘when you hear hooves, think horses not zebras’ (i.e. most presentations have a common cause) and usually it is good advice. Fever is a very common paediatric presentation and usually has an identifiable infectious aetiology. However, for the child with prolonged fever it is sometimes necessary to look beyond the usual suspects and consider the ‘zebra’ diagnoses. This article addresses when to consider rarer and potentially life-threatening infective, autoimmune or malignant causes of prolonged fever and their immediate management.