Fever is one of the most common presenting complaints in childhood and is most frequently due to infection. Young children experience, on average, three to six febrile episodes per year. Most have a self-limiting, presumed viral illness. Around 5 - 10% of those presenting to an A&E department have a serious bacterial infection (Craig et al., 2010). If fevers are prolonged, recurrent, or periodic, other differential diagnoses including immunodeficiency, malignancy and inflammatory conditions should be considered (Soon and Laxer, 2017).
Fever patterns:
- Prolonged fever – fever longer than expected for the clinical diagnosis e.g. viral syndrome lasting more than 10 days
- Fever of unknown origin – single episode lasting more than 3 weeks, during which fever is above 38.3°C on most days, uncertain diagnosis after 1 week of investigation
- Recurrent fever – single episode during which fever waxes and wanes, or repeated febrile episodes
- Periodic fever – recurring episodes lasting days to weeks in which fever is the main feature, well in-between episodes (Long, 2005)