Fever Without An Obvious Source

Fever without an obvious source describes fever in which history and examination do not identify a clear focus. The probability of serious bacterial infection is strongly age dependent.

Young infants require particularly cautious assessment because bacteraemia, UTI and meningitis may present without localizing features.

The child may have fever alone or nonspecific features such as:

• Irritability
• Reduced feeding
• Lethargy
• Vomiting

A clinically unwell appearance significantly increases concern regardless of temperature magnitude.

Urinary infection is one of the most important occult bacterial infections and urine assessment should be considered particularly in younger children.

In high risk infants evaluate:

• FBC
• Blood culture
• CRP or procalcitonin where available
• Urinalysis and urine culture
• CSF where meningitis risk is significant

Malaria testing is appropriate where epidemiology or exposure supports it.

Management depends on age and risk stratification.

A toxic or haemodynamically unstable child requires immediate sepsis management and empirical IV antibiotics after cultures where possible.

Well appearing older infants and children with reassuring assessment may be observed without empirical antibiotics when reliable follow up is available.