Traditionally, pediatricians tell families that teething does not cause a fever (a body temperature of 100.5 degrees or greater). Pediatricians do not want families to dismiss a fever when there may be a more serious cause. Parents feel more comfortable placing blame for the fever on something they cannot control (teething) versus something they potentially can control (another illness after an exposure to someone else who was ill).
Pediatricians base their recommendation on many things. One is that there was a large study of young children in the "teething age" (3 months to 2 1/2 years of age) who where carefully screened for bacteria or viruses when they had a fever but little other symptoms. Over 85% of this group were found to indeed have a virus (usually) or bacteria (less often). Many times, as your immune system fights off an infection, the only symptom is a fever. The authors of the study felt it was likely there were even more fever-causing germs they did not find.
We certainly do find some of these not-too-sick-appearing feverish children do have a viral or bacterial infection that needs some attention. Some of these would include urinary tract infections, ear infections, and viral or bacterial throat infections. Another common viral infection to cause a prominent fever with little other symptoms (until a rash occurs when the fever breaks) is roseola.
On an interesting note, a study published last year on infants in Italy showed that they found temperatures peaking at 100.6 degrees with infants that they felt had no other sign of infection. The limiting factors in this study is that the temperature was only taken once a day by the researchers and they were not doing any lab studies to confirm or deny the idea that there may be viral or bacterial infections that were not evident on exam.
So we want you to not assume that a fever is from teething. The usual worrisome things about fever (not perking up when the temperature comes down, a fever for five straight days, temperatures of 106 degrees or more) should be taken seriously. And remember these important facts about fever: fevers are caused when your immune system is trying to fight off an illness; we treat fevers for comfort reasons (not because they are dangerous) until the temperature is 108 degrees or more; and the chances of your child having a "dangerously high" fever (108 degrees or more) is very, very unlikely. Make sure you read our "Fever" protocol on our website here.