Fever and Teething in Babies
Teething does not cause clinically significant fever, and any fever ≥38.0°C (100.4°F) in an infant requires evaluation for serious bacterial infection rather than attribution to teething alone.
The Evidence Against Teething as a Cause of Fever
The relationship between teething and fever has been extensively studied, and the evidence is clear:
A prospective cohort study of 236 tooth eruption days found no association between tooth eruption and fever (OR = 1.35,95% CI = 0.80-2.27 for high fever; OR = 1.34,95% CI = 0.48-3.77 for low fever), with child temperatures essentially identical on tooth eruption days versus non-tooth days (36.21°C vs 36.18°C) 1.
Only 20 of 46 infants had fever >37.5°C on the day of first tooth eruption, emphasizing the danger of attributing fever to teething and potentially missing serious illness 2.
Teething does not cause fever, diarrhea, rashes, seizures, or bronchitis, though it may be associated with minor symptoms like daytime restlessness, gum rubbing, and drooling 3.
Critical Evaluation Required for Fever in Infants
When a baby presents with fever, regardless of concurrent teething, the following algorithmic approach is essential:
Age-Specific Risk Stratification
For infants <90 days old:
- Any fever ≥38.0°C (100.4°F) requires immediate evaluation for serious bacterial infection, including potential lumbar puncture, blood cultures, and urinalysis 4.
- Cerebrospinal fluid pleocytosis risk is 8.8% in febrile infants ≤90 days, with bacterial meningitis occurring in 0.35% 4.
For children 3-36 months old:
- If temperature ≥39.0°C (102.2°F) with no identifiable source and WBC ≥15,000/mm³, consider empiric antibiotic therapy to prevent progression of occult bacteremia to meningitis 4.
- The risk of meningitis among untreated children with occult pneumococcal bacteremia is approximately 3%, which antibiotics significantly reduce 4.
Essential Diagnostic Workup
Urinary tract infection evaluation:
- UTI accounts for >90% of serious bacterial infections in children aged 2 months to 2 years 5.
- Obtain urinalysis with leukocyte esterase, nitrites, and microscopy via catheterization (contamination rate 12% vs 26% for clean catch) 5.
- Obtain urine culture before starting antibiotics if urinalysis is positive 5.
Pneumonia assessment:
- Tachycardia out of proportion to fever is a Level B predictor of pneumonia, and chest radiograph should be obtained, especially with fever ≥39°C, cough, or hypoxia 5.
- The combination of tachycardia, tachypnea, cough, hypoxia, rales, high fever, and fever duration >48 hours has 94% sensitivity for radiographic pneumonia 5.
Symptomatic Management of Fever
Once serious bacterial infection is excluded or appropriately treated:
- Use antipyretics (acetaminophen or ibuprofen) only when fever is associated with discomfort, not routinely for all fevers 6.
- Dose antipyretics based on weight rather than age, with oral acetaminophen preferred over rectal administration 6.
- Combined or alternating use of antipyretics is discouraged 6.
- Acetaminophen is FDA-approved as a pain reliever/fever reducer 7.
Management of Teething Symptoms (Without Fever)
For actual teething-related discomfort without fever:
- Local gingival treatments or homeopathic agents like Camilia® provide similar benefit to topical therapy for buccogingival symptoms 8.
- Most infants (96.6%) have buccogingival symptoms during teething, but these are distinct from fever 8.
Critical Red Flags
Instruct parents to return immediately if the child develops:
- Altered consciousness or severe lethargy 5
- Respiratory distress or signs of dehydration 5
- Persistent vomiting or petechial/purpuric rash 5
- Fever persisting ≥5 days 5
Common Pitfall to Avoid
The most dangerous error is attributing fever to teething and failing to evaluate for serious bacterial infection. Illness occurring with teething should be thoroughly evaluated so that serious systemic disturbance is not overlooked 3. This is particularly critical because parents retrospectively report strong beliefs that their children suffered teething symptoms, despite prospective evidence showing no such associations 1.