Month 8 Worry: Is Fever Dangerous to My Infant?Dr. Greg Germain, MD
My phone rings in the middle of the night. An anxious parent is at the other end of the line: “My infant felt warm, I took her temperature, it’s 102. What do I do now?” This is by far the most common emergency call I get. Will you be ready for your baby’s first fever?
What’s the Issue?
Almost all infants will have at least one episode of fever by their first birthdays. Some babies will have many. Fever is defined by most pediatricians as any temperature (rectal is still the gold standard for infants) at or above 100.5 (38 C). A febrile (what doctors call “feverish”) infant is cranky, harder to console than usual, and naturally worrisome to parents.
Most parents I talk to are either worried about serious bacterial illness or that the height of the fever is dangerous to their baby. “Will my baby have a seizure?” “Will my baby suffer brain damage?” The short answer is this: fevers are short-lived, normal, and totally benign.
Consider the Numbers
Five percent of all children will have a seizure with fever during early childhood. There is nothing you can do to prevent it. This is a terrifying event to witness as a parent, but almost never medically dangerous. A seizure in an infant is tonic (involves muscle tensing or stiffening), clonic (involves shaking or rhythmic muscle movement), and generalized (infants are unconscious and unaware of their surroundings).
If your child has a seizure with or without a fever, dial 911 and let a physician sort out the cause. It is likely that many children have unrecognized febrile seizures in their sleep—ones parents never know about. Of those kids who do have febrile seizures, there is a 50 percent chance that they will have another before their fifth birthdays. Babies who have a second febrile seizure within 24 hours of their first are rare and require more intense medical work-up or observation.
Viral infection is, by far, the most common cause of infant fever. These fevers can last 72 hours and reach heights of 105+. An infant’s body can handle temperatures of this height without any consequences. Brain damage is thought to occur at temps of 107 to 108. The most common cause of dangerously high infant temperatures (hyperthermia) is not infection (this almost never happens), but infants locked unattended in cars.
Parents of very young babies, please note: Call your clinician immediately, no matter what time of day or night, if an infant younger than three months has a temp of 100.5 or higher. Because of their immature age, these febrile infants have a three percent chance of serious bacterial illness, which warrants immediate attention.
What Parents Can Do
Stay calm. Fever is a sign that your child is fighting an infection, but also a sign that your baby’s immune defenses are working well. When a body senses an “invader,” (most likely a virus) it cranks up the thermostat so that the invader can be killed. Your body (and your infant’s body) knows that viruses and bacteria don’t exist well at high temperatures. Thus, the brain (specifically, the hypothalamus) raises the temperature in an effort to protect your infant from infection. The bottom line: fever is a good thing!
So what do you do when you are at Grandma’s house and the temperature is too high? Well, if you’re like me, you sneak over to the thermostat and turn it down a degree or two. (Don’t tell my grandma.) That’s what acetaminophen, the generic name for infant Tylenol, does. (Generic is just as effective as the more costly name brand, by the way.) Acetaminophen directly affects the brain’s thermostat to lower your infant’s temperature an average of one degree. That one degree doesn’t seem like much, but it is certainly enough to take the edge off and make your infant more comfortable, perhaps allowing her to get back to sleep. (Use this acetaminophen dosage chart.)
What should you NOT do for a febrile infant?
- Do not put your baby in a tepid bath. Your goal is to provide comfort measures, and nothing makes a baby more irritable than a tepid bath in the middle of the night. Would it make you more comfortable?
- Don’t go to the ER. The doctor will yawn and send you home after a lengthy wait. Even worse, the doctor might feel obliged to do a set of well-meaning but unnecessary tests. (Of course, there are other symptoms that can go hand-in-hand with fever and do necessitate emergency care. See tips on when to call your pediatrician below.)
- Don’t give more than the recommended dose of Tylenol or give it more often than the recommended frequency. More is NOT better. In fact, too much Tylenol is far more dangerous than the fever itself: Tylenol is best dosed by weight, not by age. So if you have a 40-pound two-year-old, he should be dosed based on weight, or as if he were four years old.
- And most importantly, don’t panic. Fevers go down as quickly and dramatically as they go up.
Besides infant Tylenol, what CAN make babies with fever more comfortable?
- Consider offering ibuprofen, at the recommended dose for Baby’s weight, if Tylenol hasn’t worked within 45 minutes (the typical time is takes Tylenol to start to work).
- Offer small amounts of fluid frequently to avoid dehydration, as fever can dehydrate an infant quickly.
- Use any comfort measure that seems to work: extra cuddling, a cool cloth on the forehead or the back of the neck, fewer layers of clothes, more frequent nursing, etc.
DO call your pediatrician if your infant is:
- Hard to console, despite having waited for a correct dose of Tylenol to kick in.
- Dehydrated—she has no urine output for more than six hours.
- Having any breathing difficulties, such as audible wheezing, struggling to get air in or breathing more than 60 times in a minute.
And certainly call if your parental instincts tell you there is something seriously wrong.
What the Docs May Do
Reassurance, reassurance, reassurance! I spend a lot of time both on the phone and in the office calming parents about their febrile infants. Pediatricians check many infants on a daily basis and find no bacterial cause for concern. These parents and infants leave the office with a viral diagnosis, some parental peace of mind, and a list of things to watch for (see above). I never refuse to see a concerned parent in the office, but often will suggest they wait until the fever has brewed for 72 hours unless there is some other cause for concern.
Infants who have had their first febrile seizure require a detailed retelling of the story and a careful physical exam. If everything checks out—that is there’s nothing worrisome or atypical in the story or exam—these babies go home with their parents. Parents of infants who have recurrent febrile seizures are taught to manage them at home. These infants grow up to be normal kids, in general, and outgrow febrile seizures by about age five.
More 8th Month Health Help
Even the most confident parent has concerns about her child’s health and wellness from time to time. (If you have any pressing concerns or questions about your baby’s health, please check with her healthcare provider.)
- What was last month’s most popular health worry?
- Learn which medical question you might have next month.
- Here’s what else is happening with your baby’s health and development this month.