Pediatric Fever Without a Source - 3 months to 3 years

Author: Christine Cho, MD
Updated: 2/9/2012

Pediatric Fever Without a Source: 3 months to 3 years

  • Fever that should prompt workup in this age group: T ≥39.0°C / 102.2°F
  • Fever still defined as T ≥ 38°C / 100.4°F
  • Named viral infections DO count as a source, such as: HSV gingivostomatitis, Coxsackie hand-foot-mouth, RSV bronchiolitis (although UTI may present concurrently with RSV)
  • Unnamed, nonspecific viral infections MAY be considered a source for vaccinated, well-appearing child (especially with sick contacts)


Serious bacterial infection (SBI) includes:

  • Occult bacteremia: Most commonly Strep pneumoniae
  • Meningitis: <0.03% risk in post-PCV7 vaccination era. Clinical exam is helpful.
  • UTI: 60-65% of febrile UTI patients have pyelonephritis
  • Pneumonia: Most common pathogens are viruses in post-PCV7 era
  • Also: Gastroenteritis, osteomyelitis, septic arthritis, soft tissue infection

Workup Guidelines (if nontoxic appearing)


Age Diagnostic Testing
≤ 24 months Urinalysis, urine culture
> 24 months No urine studies


Age Circumcised Uncircumcised
≤ 6 months Consider urinalysis and urine culture Urinalysis, urine culture
6-12 months No urine studies Consider urinalysis and urine culture
> 12 months No urine studies No urine studies

Urinary Tract Infection (UTI) Diagnosis

Any of the following findings on UA:

  • Positive LE
  • Positive nitrites
  • ≥10 WBC/hpf

Additional Workup Beyond Urine Studies Based on Number of Pneumococcal Conjugate Vaccines (PCV)

Workup relative to number of pneumococcal conjugate vaccines