Fevers are a very common symptom in children. A child's body temperature changes during the day, so get an accurate measurement when you feel your child has a fever. A child with a fever can have anything from a mild illness to a serious medical condition, so it is important to identify other symptoms your child may have in order to make an accurate diagnosis.
Function
Fevers are part of the body's response to infection. According to the Merck Manuals website, fevers boost the body's defenses against microorganisms. For example, bacteria produce substances called pyrogens that trigger the brain to raise the body's temperature. By doing this, the brain attempts to create an inhospitable environment for bacteria to reproduce. Also, the rise in the body's temperature favors the proliferation of immune system cells, which go on to fight the invading microbe.
Features
Fevers in children are defined as an increase in the body's core temperature. There are different ways to check your child's temperature, and depending on the method, the threshold for calling a fever varies. The best way is with a rectal thermometer. A rectal temperature of 100.4 degrees F or higher is considered a fever. When measuring with an axillary or armpit thermometer, a temperature of 99 degrees F or higher is considered a fever. If you check the temperature of your child with an oral thermometer, a measurement above 100 degrees is considered a fever as well.
Significance
Although we routinely associate fevers with infections, there are others conditions that can elicit fevers in a child. Autoimmune disease, in which the body mistakenly attacks its own tissues, can cause fevers. Some autoimmune conditions include lupus and juvenile idiopathic arthritis. Other conditions that might cause fever include cancer and vasculitis, or an inflammation of the blood vessels. Fevers in these conditions are usually hard to control and last longer than five days.
Considerations
Fever control is important, but only if the child is uncomfortable, appears ill, is having trouble sleeping, or is dehydrated. If the fever is mild and the child appears well, no intervention is necessary.
Misconceptions
A commonly held belief is that teething in young children can cause fevers. This is not true. Other misconceptions regarding fevers are that they can cause impotence. Fevers that cause brain damage can occur, but only in a condition called hyperpyrexia, an unusual situation in which the body's temperature raises to above 107 degrees F. Fevers can cause seizures, but these febrile seizures are caused not by the height of the fever but by a sudden rise in the body's temperature. Febrile seizures are benign and have no long-term consequences.
