Keywords: Procalcitonin, febrile infants, sepsis (PubMed Search)
Young infants (0-90 days) have immature immune systems and are at higher risk for serious bacterial infections, particularly urinary tract infections, bacterial meningitis, and bacteremia. Infants less than 90 days old have an incidence of bacterial infections between 8 to 12.5%, while infants less than or equal to 28 days old have almost a 20% incidence.
Risk-stratification of this group has been a huge focus of research over the past couple of decades to help identify which patients require a full sepsis work-up, particularly in well-appearing infants if a source of fever is identified early. Recent studies have explored the utility of biomarkers in risk stratification in this population. A better ability to discriminate would hopefully decrease unnecessary lumbar punctures, antibiotic use, and hospital admission. Multiple studies have shown procalcitonin is able to outperform CRP for prediction of serious bacterial infections. Kuppermann et al developed a tool to identify low risk febrile infants < 60 days using procalcitonin and ANC. Their prediction rule gave a 97.7% sensitivity, 60% specificity, and 99.6% NPV for serious bacterial infection. There have been several other studies that have looked harder to detect infections such as osteomyelitis or septic arthritis across all pediatric patients and the data has not been as promising.
Bottom line: Procalcitonin shows promise as part of a risk stratification tool in infants younger than 60 days. Other studies have failed to show its relevance as a screening tool for osteomyelitis, septic arthritis, renal abscess or community acquired pneumonia.
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