Children and fevers: The myths and facts

A child with fever is one of the most complex problems in the field of pediatrics. Unlike adults, children will respond to simple viral infections with spectacular elevations in temperature.  The approach to the febrile child varies depending on the child’s age, state of health, and associated symptoms. 

While a myriad of studies have been published on the subject, there is surprisingly little evidence that provides definitive guidance so I will try to focus on several myths and facts when it comes to children with fevers.

Myth #1:  Any temperature over 98.6 F is a fever.

Like height and weight, body temperature varies from individual to individual. Moreover, the body temperature later in the day tends to be significantly higher than temperatures early in the morning; this is called diurnal variation. 

Myth #2: Taking a temperature rectally yields a higher result than if the temperature is measured orally, in the axilla (armpit), or tympanically (in the ear). 

The several studies on this topic suggest there is much more variation in measurement when the temperature is measured in the arm pit, orally or ear compared to rectally. Given the discomfort with rectal temperatures, these other methods are acceptable as long as directions are followed. In children 4 weeks to 5 years of age, temperature should be measured in the arm pit or ear; under 4 weeks of age, use only the arm pit method.

Myth # 3: Fever causes epilepsy in children.

This is not quite true. Febrile seizures occur in approximately 4 percent of American children, tend to be short-lived and, in normal children, do not affect long term intellectual or physical ability. Children with developmental or neurological disorders who have febrile seizures are at an increased risk for developing epilepsy.  Since some seizures with fever may be caused by an underlying infection or other problem, all of these children should be evaluated immediately by a healthcare provider.

Myth # 4:  Acetominophen (Tylenol) or ibuprofen will prevent febrile seizures.

This is untrue. A well controlled, randomized trial failed to demonstrate any impact of temperature lowering drugs on the incidence of febrile seizures in children. 

Myth #5:  Alternating Acetaminophen and ibuprofen provides better fever control than either drug alone.

This has also been studied in detail. While several studies have shown improved temperature control four or more hours after initiation of combination therapy, there is no evidence that this approach results in any changes in overall outcome of the illness.  Given the increased possibility for side effects, many practitioners prefer to use a single agent. 

Now that we've gone through the myths, here are some facts about fevers in children and when you should seek care by a health care professional.

Fact # 1: A recorded temperature over 100.4 F in a child 3 months of age or less should be evaluated immediately by a healthcare professional.

A large number of studies have shown that the risk of serious bacterial infections in infants this age with a temperature of 100.4 F or greater is between 7 to 12 percent.  Infants less than 30 days of age, those who were premature, have received antibiotics previously or have a site of infection such as an ear infection are at greatest risk. 

Fact #2:  A recorded fever of 102.2 F or more in any child 3 to 6 months of age should be immediately evaluated by a health care professional. 

Since vaccinations usually begin at 2 months of age, children in the 3 to 6 month age group are not fully vaccinated.  As such the risk for serious bacterial infection is higher in this group than in older children. 

Fact #3: Beyond 6 months of age, the height of the fever beyond 100.4 F is not an indicator of risk for serious infection in otherwise healthy children.

Once children reach 6 months of age and are fully immunized, the risk of serious bacterial infection is greatly reduced.  So when should you seek care for your febrile child?  The best guidelines are from the National Institute of Health Care and Excellence, a British organization tasked with providing best practices for British physicians. It recommends seeking care if:

  • your child develops a non-blanching rash (a rash that does not disappear with pressure)
  • your child has a convulsion (also known as a fit or seizure)
  • your child's health gets worse
  • the fever lasts consistently for more than five days
  • you are becoming more worried about your child; particularly if your child becomes more irritable or difficult to awaken
  • you have concerns about looking after your child at home.

Fact #4:  You can care for your child at home by ensuring adequate fluid intake, observing for worsening or new symptoms, using acetaminophen or ibuprofen judiciously, and contacting your healthcare provider if you feel your child is not improving or is getting worse.

Provide unlimited amounts of pedialyte (infants), water or sports drinks to your child.  Monitor hydration by looking for at least three wet diapers or voids per day.  You may give either acetaminophen or ibuprofen in recommended dosages and frequencies to your child for associated pain or if your child becomes overly uncomfortable with fever; do not use these agents simply because the temperature is over 100.4 F.  Observe for changes in your child’s condition and the appearance of new symptoms.  Contact your child’s healthcare provider if things seem to be getting worse or if you are becoming more concerned. 

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