Can teething cause fever in an otherwise healthy infant?

Can Teething Cause Fever?

Teething does not cause clinically significant fever and should never be used as an explanation for fever ≥38.0°C (100.4°F) in infants. 1, 2

The Evidence on Teething and Temperature

While teething may be associated with a mild temperature elevation (typically <38.0°C or <100.4°F), it does not cause true fever by medical definition. 2

• A large prospective study of 125 infants tracking 475 tooth eruptions found that mild temperature elevation was statistically associated with the 8-day teething period (4 days before through 3 days after tooth emergence), but no teething child had a fever ≥104°F and none had a life-threatening illness. 2

• The same study demonstrated that fever over 102°F was not significantly associated with tooth emergence. 2

• An earlier study examining the 20 days before first tooth eruption found 20 infants had temperatures >37.5°C on the day of eruption, emphasizing the danger of attributing fever to teething. 3

Why This Matters Clinically

The critical risk is missing serious bacterial infections by incorrectly attributing fever to teething. 1, 4

• In febrile infants 2-24 months without apparent source, the prevalence of urinary tract infection is 3-7%, with higher rates in girls (8.1% ages 1-2 years) and uncircumcised boys (8-12.4% in infants). 5, 6

• For infants under 3 months, 8-13% of fevers represent invasive bacterial infections, with urinary tract infections accounting for over 90% of serious bacterial infections. 7

• Infants younger than 1 year with fever without source should be considered at risk for urinary tract infection and require appropriate evaluation. 5

The Dangerous Cultural Practice

In some communities, the false attribution of fever to teething leads to harmful practices like gum lancing, which is associated with severe complications including sepsis, meningitis, and death (6.1% mortality in one series). 4

What Teething Actually Causes

Teething may legitimately cause minor symptoms only: 1, 2

• Increased biting, drooling, gum-rubbing, and sucking
• Mild irritability and wakefulness
• Decreased appetite for solid foods
• Facial rash

Teething does NOT cause: 1, 2

• Fever ≥102°F (38.9°C)
• Diarrhea
• Vomiting
• Congestion or cough
• Serious systemic illness

Clinical Approach to Fever in a Teething Infant

Any infant with documented fever ≥38.0°C (100.4°F) requires full evaluation for serious bacterial infection, regardless of teething status. 5, 6, 8

For infants 2-24 months with fever ≥38.0°C: 5, 6

• Obtain catheterized urine specimen for urinalysis and culture (never rely on bag specimens)
• Risk-stratify based on age, sex, circumcision status, fever height/duration, and presence of other infection sources
• Girls with ≥2 risk factors (age <12 months, white race, temperature ≥39°C, fever ≥2 days, no other source) have >2% UTI risk
• Uncircumcised boys have significantly elevated UTI risk even with fewer risk factors

For infants under 3 months with any fever ≥38.0°C: 7, 8

• Complete infectious workup is obligatory (blood culture, urine culture, inflammatory markers)
• Lumbar puncture is strongly recommended for infants 1-3 months old
• Do not rely on clinical appearance—58% of infants with serious bacterial infections may appear well

Common Pitfall to Avoid

Never assume teething explains fever—this delays diagnosis of potentially serious infections like urinary tract infection, bacteremia, or meningitis. 1, 3 The temporal association between mild temperature elevation and tooth eruption does not establish causation for clinically significant fever, and attributing fever to teething has led to missed diagnoses with serious consequences including renal scarring, sepsis, and death. 5, 4