Diagnosis of the child with fever in the emergency department (continuing education credit).

Abstract

Fever in young children is one of the more common complaints precipitating a visit to the emergency room. Yet in spite of a wealth of medical literature in this field, few people can even define at what temperature fever begins. It is helpful, however, to have a specific numerical point of reference. An arbitrary but useful point where fever can be said to begin is 37.5O C (99.5O F) orally or 38.1 o C (100.5“ F) rectally. The most notable exception to this rule is the patient with the possibility of appendicitis. In this case, 37.2’ C (99O F) orally or 37.8’ C (100’ F) rectally is an appropriate demarcation for the clinical sign of fever. Lowering the expectation of where fever begins in patients with appendicitis is done out of respect for the subtle signs with which children who have that disease may be seen initially. Some 100 years ago, Wunderlich reintroduced the concept that body temperature as measured by a thermometer may be indicative of disease in human subjects. At that time, only axillary temperatures were taken. Although some studies suggest that axillary temperatures taken by electronic thermometers are useful,’ in 1984 Kresch determined that axillary temperature taken using a glass thermometer is quite insensitive for the detection of fever. In this study, using 37.3’ C (99.1’ F) axillary temperature as the definition of fever, axillary measurement detected only 33.3% of febrile patients. And when a fever was found by axillary measurement, it was confirmed by rectal temperature only 78% of the time.2 The argument is often made that rectal temperatures are dangerous to perform because of the possibility of bowel perforation.3 This risk can be lowered by taking rectal temperatures more carefully.4 A new concern about rectal thermometry relates to anxieties about the transmission of human immunodeficiency virus (HIV, the agent of acquired immunodeficiency syndrome [AIDS]). It has been demonstrated repeatedly that HIV is easily inactivated using standard reagents (including 40% ethyl alcohol, 1% lysol, 5% phenol, 200 ppm sodium hypochlorite, NP-40, hydrogen peroxide, phenolics, and paraformaldehyde). As long as fecal debris, which a reagent might not be able to penetrate, is removed from the thermometer, chemical disinfection will be more than adequate to eradicate the virus.5 The diurnal cycle of human body temperature should not alter the previously mentioned guidelines of what temperature constitutes fever. The daily minimum body temperature occurs between 2 and 4 AM, and the daily maximum temperature occurs some 12 to 16 hours later. The range between the minimum and maximum values is about one half a degree centigrade. The child with a high fever is commonly seen in the emergency department with a concerned parent and offers both a problem and an opportunity to the ED nurse to calm the parent and to comfort the child. The parents should be asked what they’ve already done for the child. Specifically, it is important to find out what medications have been given, in what dose, and when. (Depending on the gravity of the situation, it may sometimes be appropriate to send someone home to retrieve a medicine if its name can’t be recalled.) No matter how little the parents have done,