Classification and Management of Fever in Children

Definition and Measurement of Fever

Fever is defined as rectal temperature >38°C (>100.4°F), which remains the gold standard for accuracy in young children 1, 2
Other temperature measurement methods have lower reliability and must be interpreted in clinical context 1

Fever without localizing signs is defined as acute onset fever (<1 week duration) with absence of localizing signs on examination 3
At age 4 years, the risk of serious bacterial infection is significantly lower than in infants, particularly in the post-pneumococcal vaccine era 2, 3
Fever of unknown origin is typically defined as prolonged fever (≥5 days duration) without identified source 4

High-risk features requiring immediate evaluation include toxic or ill-appearing child, extreme lethargy or altered consciousness, and signs of septicemia 5, 3
Urinary tract infection prevalence in febrile children without source is approximately 3-7% overall, with higher risk in girls (8.1% at ages 1-2 years) compared to boys (1.9%) 6
Any child with prolonged unexplained fever or known urinary tract anatomic abnormality should be evaluated for UTI 6

The primary goal in managing fever is improving overall comfort, NOT normalizing temperature 4
Antipyretics (acetaminophen or ibuprofen) should be used ONLY when fever causes discomfort, not routinely, and dosed based on weight, not age 4
Children with fever >38.5°C AND chronic disease OR features like breathing difficulties, severe earache, vomiting >24 hours, or drowsiness require antibiotics 5
Co-amoxiclav is the antibiotic of choice for children under 12 years, with clarithromycin or cefuroxime for penicillin-allergic children 5

Never rely solely on clinical appearance, as many children with serious bacterial infections may appear well initially 3, 4
Account for recent antipyretic use, as this may mask fever severity and serious infection 3, 4
Do not assume viral infection excludes bacterial coinfection, as presence of viral infection does not exclude coexisting bacterial infection 3, 4