Teething begins when a baby’s first tooth starts to break through the gum line, typically around six months of age, though timing varies widely. This process can last for two years until all twenty primary teeth have emerged, frequently causing parental concern over discomfort. A common worry is whether cutting teeth can cause a fever. Understanding the difference between a minor temperature change and a genuine fever is important for parents seeking medical advice.
Teething Symptoms and the Scientific Consensus on Temperature Elevation
The medical consensus is clear: teething may cause a slight increase in a baby’s temperature, but it does not cause a true fever. A true fever is medically defined as a temperature of \(100.4^{\circ}\text{F}\) (\(38^{\circ}\text{C}\)) or higher, and teething is consistently associated with readings below this threshold.
The process involves a localized inflammatory response in the gum tissue as the tooth pushes through, causing a minor temperature elevation, often just a few tenths of a degree. This slight rise is considered a mild reaction to localized irritation and is not high enough to classify as a fever.
Common signs of teething are centered on the mouth and associated discomfort. These include increased drooling, which can sometimes cause a facial rash, and mild swelling or redness of the gums. Babies will often exhibit increased irritability, gnaw or chew on objects, and experience disturbed sleep patterns.
Recognizing True Illness
Since a high temperature is not a symptom of teething, a true fever of \(100.4^{\circ}\text{F}\) or higher usually indicates a concurrent viral or bacterial infection. Teething often occurs when infants lose passive immunity from their mother, making them more susceptible to common childhood illnesses. Attributing a significant fever to teething can be dangerous, risking delayed diagnosis and treatment of an underlying infection.
Parents should look for symptoms that point away from simple teething discomfort. Signs of an actual illness that warrant immediate medical attention include:
- Vomiting
- Diarrhea
- Nasal congestion and a persistent cough
- Lethargy or extreme drowsiness
- A skin rash unrelated to drooling
- An overall appearance of being significantly unwell
Such symptoms suggest an infection, requiring a proper medical evaluation.
Fever Thresholds and When to Call the Doctor
A temperature reading of \(100.4^{\circ}\text{F}\) (\(38^{\circ}\text{C}\)) or higher, taken rectally, defines a fever in an infant. The age of the baby is the most important factor in determining the urgency of medical contact.
Age-Specific Guidelines
Any fever in an infant under three months old requires immediate evaluation by a pediatrician or a trip to the emergency department.
For babies between three and six months old, a fever exceeding \(102^{\circ}\text{F}\) (\(38.9^{\circ}\text{C}\)) should prompt a call to the doctor. For older babies, a temperature reaching \(104^{\circ}\text{F}\) (\(40^{\circ}\text{C}\)) is a cause for serious concern.
A fever that lasts longer than 24 hours in a child under two years old, or persists for more than 72 hours in an older child, should be addressed by a healthcare provider, regardless of the exact temperature reading. Parents should also call the doctor if any fever is accompanied by severe symptoms like difficulty breathing, a stiff neck, or extreme drowsiness.