Fever Facts:

A fever occurs when the body temperature of an individual is above the normal value.  Typically, a rectal temperature above 100.4 degrees F is considered a fever, and this value is slightly lower for a temperature taken under the arm (99.5 degrees).  A person's temperature can fluctuate during the day, and can be almost a full degree higher at night time.  Exercise, warm baths, hot weather, or excessive clothing can all cause mild temperature elevations.

A fever can develop when the body's internal thermostat, which is controlled by a part of the brain called the hypothalamus, has a higher "set-point".  This occurs after chemicals called pyrogens are released from certain types of white-blood cells.  These pyrogens are responding to substances that come from OUTSIDE the body (such as infections, malignancy, drugs, rheumatologic disease, and others).  The pyrogens then stimulate the hypothalamus to produce a chemical called prostaglandin (PGE2), which leads to the conservation and production of heat, which then raises the body's core temperature.   

In general, in the pediatric population, the majority of fevers are caused by viruses and only last for about 3 days; certain viruses like influenza and EBV can be associated with longer fevers. A rectal temperature above 100.4 in a baby during the first several weeks of life could be a sign of a more serious infection and this requires prompt medical evaluation.  A fever does not cause brain damage and is generally not harmful when less than 106 degreesF; however, a fever this high could be a sign of a more serious bacterial infection, such as a kidney infection or sepsis.  Many people also mistakenly attribute fever to teething.  Teething will not cause a fever above 101.

 With a low-grade fever, such as below 103 degrees, fever-reducing medication is not necessary in a healthy child.  A child may be more comfortable when medicated, but this will not affect the underlying source of the fever.   More aggressive treatment of fever is advised for patients that have chronic heart or lung disease, as well as patients with chronic anemia, or metabolic disorders (such as diabetes). In addition, there is about a 5% chance of benign febrile seizures in children between the ages of 3 months and 5 years, and patients with this history are usually aggressively treated with fever reducer when a fever does present.  While benign febrile seizures are scary for parents to witness, they generally are not associated with epilepsy (seizure disorder) later in life. 

The two main classes of fever reducers in pediatrics are Acetaminophen (Tylenol) and Ibuprofen (Motrin, Advil).  While neither class of medication is necessary for low-grade fevers, they can both be used if the febrile child is also very irritable or uncomfortable.  Parents have gotten into the habit from advice of health-care providers or friends to alternate, or stagger the dosing of BOTH Ibuprofen and Acetaminophen.  While this is acceptable for a patient who is very uncomfortable with a higher fever, it is not advised for low-grade fevers.  Care must be taken to only give each class of medication using it's respective dosing schedule (Acetaminophen every 4 hours, as needed; Ibuprofen every 6 hours, as needed).   Aspirin is NOT advised in pediatric use because of it's association with Reye Syndrome, resulting in potential brain injury.

In summary, please don't panic when your child has a fever.  Encourage fluid intake, dress in lighter clothing, and use fever reducers if your child is uncomfortable or irritable with the fever.  Though sponging is one of those age-old practices, it may actually cause the child to shiver, which ultimately can cause the temperature to rise further.

Mark C. Garabedian, M.D., F.A.A.P.
Dr. Garabedian received his medical degree from New York Medical College and completed his residency in Pediatrics at North Shore University Hospital and Cornell University Medical Center. He is board certified by the American Academy of Pediatrics. Prior to joining Bon Secours Medical Group, Dr. Garabedian was in private practice in Southampton, New York, for 16 years. He is now working with Hanover Pediatrics , a Bon Secours practice.