Fever in Children


  • Assessment must differentiate the well child from the unwell child, while identifying the source of infection where possible
  • All children under 28 days require investigations (FBC, U&E, CRP, blood, urine and CSF cultures) and admission for IV antibiotics
  • All children between 1-3 months old require a senior review, with investigations based on senior assessment and subsequent admission under paediatrics

Definition of fever

  • Temperature of 38°C and above
  • Use an axillary thermometer in infants (under 12 months)
  • Use a tympanic thermometer in children over 12 months


Vital components of History

  • Localising symptoms
  • Duration of fever
  • Travel
  • Regular & current meds (i.e. partially treated meningitis with oral antibiotics)
  • High risk past Hx: prematurity, chronic lung disease, cardiac malformation, immunosuppression, previous sepsis, indwelling devices
  • Immunization status

Key components of physical exam.

Step 1: Differentiate the well v unwell child

Colour Pallor* (including parent/carer report)
Activity Lethargy or decreased activity*
Not responding normally to social cues
Does not wake or only with prolonged stimulation, or if roused, does not stay awake
Weak, high-pitched or continuous cry
Respiratory Grunting
Increased work of breathing
Circulation and Hydration Poor feeding*
Dry mucous membranes
Persistent tachycardia
Central CRT ≥3 seconds
Reduced skin turgor
Reduced urine output
Neurological Bulging fontanelle
Neck stiffness
Focal neurological signs
Focal, complex or prolonged seizures
Other Non-blanching rash
Fever for ≥5 days
Swelling of a limb or joint
Non-weight bearing/not using an extremity

Pallor, poor feeding or decreased activity on their own may not suggest a seriously unwell child. Adapted from: Feverish illness in children NICE guideline 2019.

Step 2: Localizing the source of infection

  • ENT exam.: including assessment of cervical lymph nodes
  • Neuro exam.: GCS, fontanelles, gait, meningism: kernig's & Brudzinski signs
  • NB: Signs of meningism are unreliable in children under 60 days
  • Cardiac exam.: Assess for murmurs & bilateral femoral pulses
  • Resp exam.: Assess for wheeze or focal crackles
  • GI/GU exam.: Assess for abdo./flank tenderness, organomegaly and bowel sounds
  • MSK exam.: Assess all joints, looking for osteomyelitis/septic arthritis


Consider sending a urine for culture and microscopy if:

  • All febrile infants under 3 months
  • Fever 24-48 hours in children < 12 months or Hx of UTI
  • Fever >48 hours with no clear focus or preverbal children

Extra points:

  • Do not rely on point of care dipstick
  • If a child is well, it is reasonable to discharge on the advice that parents return a sample to the GP
  • However, a child who has not produced urine in the past 6 hours should not be discharged from the ED until they do so
  • Stool sample for culture, if diarrhoea present > 7 days or evidence of blood or mucous in stool
  • Bloods should only be ordered if they will change Mx. (low yield apart from blood cultures)
  • Pneumonia is a clinical diagnosis. CXR should only be requested if it will change management (e.g. suspected empyema)


a) the well child

  • Treat the source of infection
  • Can be discharged while febrile, once vital signs are normal
  • Viral illness can present without an obvious focus and GP follow up can be arranged within 48 hours if otherwise well
  • Recommend one antipyretic (paracetamol or ibuprofen), unless treating a painful condition such as tonsillitis
  • Avoid aspirin due to risk of Reye's syndrome

b) the unwell child

  • Seek early senior advice
  • Commence resuscitation and appropriate antibiotic therapy
  • Admit

c) Fever in children <3 months

  • Always suspect CNS infection, even when an alternative source of infection has been identified
  • Full septic work-up should be commenced, including lumbar puncture (LP may be deferred in a well infant >28 days if there is a clear focus of infection e.g. UTI, and senior advice has been sought)
  • Liaise early with Paed. Reg. on call

d) fever > 7 days

  • Seek senior advice
  • May require full septic screen
  • Be alert for signs of kawasaki disease

Discharge Rules

  • Child's vital signs must be within normal range, although it is reasonable to discharge a febrile child who is otherwise well
  • Child must be walking and talking (age appropriate)
  • Child must look well (i.e. non toxic)
  • Child must be tolerating oral fluids and have passed urine within the past 6 hours
  • Always provide a parental information leaflet prior to discharge


Content by , Dr Joseph Slowey, Dr Emmanuelle Fauteux-L, Dr Rory O'Brien. Last review 31/08/22.