The major issue in young children who present with a fever is to distinguish between those who will have an uneventful course and those who are at risk of serious morbidity or mortality. The American College of Emergency Physicians reviewed the evidence to develop guidelines for the evaluation of young children with fever.

Guidelines were developed by grouping together specific questions. The first question involves age cutoffs for different strategies. Because serious bacterial infections often were missed in children 28 days or younger, infants in this age range should be presumed to have a serious infection. The second question involves whether a response to antipyretic medication is associated with a lower likelihood of serious bacterial infection in young children. The evidence does not support this relationship. The third question involves indications for chest radiograph in children with fever. There appears to be fair evidence that a chest radiograph should be obtained in children three months or younger when there is evidence of pulmonary infection. In children older than three months, the indications for chest radiography are less clear, although there is an opinion that chest radiography be considered in children with a temperature greater than 102.2° F (39° C) and a white blood cell (WBC) count greater than 20,000 cells per mm³(20 × 10⁹cells per L). In children older than three months with fever but no elevated WBC count, radiography is not indicated if there are no symptoms of acute pulmonary disease.

Because urinary tract infections are a common cause of fever among young children, the fourth question considers which febrile children are at risk for urinary infection. Urinary tract infection should be considered in children younger than one year who have no other obvious source of infection. There is fair evidence that girls aged one to two years without any other source of fever should be considered at risk for urinary tract infection. The fifth question involves the best way to collect urine for examination and notes fair evidence supporting urethral catheterization or supra-pubic aspiration. The sixth question involves the types of testing to be done on properly obtained urine and shows fair evidence for obtaining a urine culture in conjunction with other urine studies in children younger than two years because a negative urine dipstick test or microscopic examination cannot reliably rule out an infection.

The seventh question involves the prevalence of occult bacteremia in children aged three to 36 months and the frequency of serious outcomes. The prevalence of occult bacteremia is approximately 1.5 to 2.0 percent in febrile children in this age group, and approximately 5 to 20 percent of cases progress to a serious negative outcome. The final question involves the use of empiric antibiotic treatment among previously healthy febrile children with no obvious source of infection. Because of the possibility of serious outcomes even in previously healthy febrile children with no obvious source of infection, fair evidence supports the use of empiric antibiotic therapy in children aged three to 36 months with no obvious infection source who have a temperature higher than 102.2° F and whose WBC count is at least 15,000 cells per mm³(15 × 10⁹cells per L). Close follow-up is suggested for all febrile children when empiric antibiotics are not given.

In an editorial in the same issue, Baraff notes that the rate of occult bacteremia has decreased since the introduction of the pneumococcal and Haemophilus influenzaevaccines. He also notes that urine collected using a “bagged” technique usually is contaminated and not acceptable for analysis, that pulse oximetry is useful in addition to other signs of acute respiratory disease in the consideration of chest radiography, and that febrile children 28 days to three months of age can be treated on an ambulatory basis if they are found to be at low risk for serious infection.