Does teething cause fever in babies?

What does the evidence show for fever during teething?

• Teething does not cause fever or diarrhea, and a caregiver who is worried about either symptom should contact the child's health care provider rather than waiting for a new tooth to explain it away. 1
• FDA consumer guidance does list a low-grade temperature among teething's occasional, mild symptoms, alongside irritability, drooling, gum swelling, and an urge to chew on something hard, but nothing on that list describes a true fever, vomiting, or a lethargic baby. 2
• Any infant younger than 28 days old who has a fever needs a full medical evaluation regardless of how well the baby otherwise appears, because very young infants cannot reliably show the usual signs of a serious infection. 3
• For a newborn, any rectal temperature of 100.4°F (38°C) or higher should be reported to the child's provider. For an infant three to twelve months old, a temperature of 102.2°F (39°C) or higher is the threshold for calling promptly, and any fever lasting more than 48 hours in a child under two needs evaluation. 4
• Beyond the newborn period, clinicians weigh how the baby actually looks, such as feeding, alertness, and breathing, along with individual risk factors, rather than the thermometer number alone, to decide whether a fever needs same-day in-person assessment or can be watched closely at home. 3
• FDA also warns against numbing teething products that contain benzocaine or lidocaine, which have been linked to serious harm including a rare blood condition called methemoglobinemia, and against teething necklaces and jewelry, which carry choking and strangulation risk regardless of whether a fever is present. 2

Fever thresholds that need medical attention

When should I call my provider about fever during teething?

A rectal temperature of 100.4°F (38°C) or higher in a baby younger than three months needs same-day medical evaluation, since teething never adequately explains a true fever at this age. Between three and twelve months, a temperature of 102.2°F (39°C) or higher, or any fever lasting more than 48 hours, needs a call to your child's provider. Fever together with a rash, unusual sleepiness, poor feeding, repeated vomiting, or a baby who is hard to console needs urgent assessment rather than a wait-and-see approach. Breathing difficulty, blue-tinted lips, a bulging soft spot, a seizure, or a baby who cannot be woken needs emergency care immediately. Whatever the pattern, any symptom that feels beyond your usual range is a reason to call: obstetric teams expect these questions and would rather hear early than late.