The aim of the study was to evaluate the impact of procalcitonin (PCT) measurement on antibiotic use in children with fever without source.

Children aged 1 to 36 months presenting to a pediatric emergency department (ED) with fever and no identified source of infection were eligible to be included in a randomized controlled trial. Patients were randomly assigned to 1 of 2 groups as follows: PCT+ (result revealed to the attending physician) and PCT− (result not revealed). Patients from both groups also had complete blood count, blood culture, urine analysis, and culture performed. Chest radiography or lumbar puncture could be performed if required.

Of the 384 children enrolled and equally randomized into the PCT+ and PCT− groups, 62 (16%) were diagnosed with a serious bacterial infection (urinary tract infection, pneumonia, occult bacteremia, or bacterial meningitis) by primary ED investigation. Ten were also found to be neutropenic (<500 × 10⁶/L). Of the remaining undiagnosed patients, 14 (9%) of 158 received antibiotics in the PCT+ group vs 16 (10%) of 154 in the PCT− group (Δ −2%; 95% confidence interval [CI], −8 to 5). A strategy to treat all patients with PCT of 0.5 ng/mL or greater with prophylactic antibiotic in this group of patients would have resulted in an increase in antibiotic use by 24% (95% CI, 15-33).

Semiquantitative PCT measurement had no impact on antibiotic use in children aged 1 to 36 months who presented with fever without source. However, a strategy to use prophylactic antibiotics in all patients with abnormal PCT results would have resulted in an increase use of antibiotics.