The arrival of a baby’s first teeth often brings discomfort and behavioral changes, leading many parents to wonder if teething causes a fever. Attributing an elevated temperature to teething can delay the recognition of a separate illness. Therefore, understanding the scientific distinction between a slight temperature rise and a true fever is important for proper care and knowing when to seek medical advice.
The Scientific Consensus on Teething and Fever
The eruption of a tooth does not cause a clinically significant fever. The established threshold for a true fever in an infant is a rectal temperature of 100.4°F (38°C) or higher. If a baby experiences a temperature at or above this level, the cause is almost certainly an unrelated infection or illness, not the teething process itself.
Teething involves localized inflammation of the gum tissue as the tooth pushes through, which may lead to a slight, transient rise in body temperature. This minor elevation is typically classified as a low-grade temperature and usually remains below the 100.4°F fever threshold. A temperature that briefly reaches 99°F or 100°F might coincide with a tooth breaking the gum line, but it should not be mistaken for a full fever. Attributing a true fever to teething risks overlooking a more serious underlying condition that requires medical attention.
Common and Expected Signs of Teething
Symptoms associated with teething are primarily localized to the mouth and surrounding areas, alongside minor behavioral changes. Inflammation often causes the gum tissue to appear red, swollen, or tender at the site of the emerging tooth. This discomfort prompts the infant to seek relief by gnawing or chewing on fingers, toys, or other objects.
Increased drooling is a common indicator, with excess saliva sometimes leading to a mild rash on the chin, cheeks, or chest. The discomfort can manifest as mild irritability, fussiness, or slight changes in sleeping and eating patterns. Some babies rub their cheeks or tug at their ears due to referred pain sensation from the nerves in the gums. These symptoms are typically confined to the days immediately before and after a tooth emerges.
Recognizing and Managing Fever in Infants
The most accurate method for determining a baby’s core temperature is a rectal measurement using a digital thermometer, especially for infants under three months of age. A temperature reading of 100.4°F (38°C) or higher, taken rectally, confirms the presence of a fever. Wait about 20 to 30 minutes after an infant has been swaddled or taken a bath before taking a temperature reading.
Any confirmed fever of 100.4°F or greater in an infant younger than 12 weeks old warrants an immediate call to a pediatrician. For older babies, report a fever above this threshold if it lasts longer than 24 hours or if the baby appears unusually ill. Contact a healthcare provider right away if the fever is accompanied by severe symptoms, such as lethargy, difficulty breathing, an unexplained rash, or repeated vomiting or diarrhea.
Fever-reducing medications like acetaminophen or ibuprofen can manage discomfort, but parents must consult a healthcare professional first to ensure correct weight-based dosing. Never give a baby medication without a doctor’s guidance. Comfort measures such as a lukewarm sponge bath or cool compresses can also help, but the focus must remain on addressing the underlying cause of the fever.