In 2021, the AAP published clinical practice guidelines for evaluation and management of well-appearing febrile 8–60-day-old-infants. These guidelines heavily rely on the use of inflammatory markers, particularly procalcitonin, to stratify the risk of important bacterial infection (defined as urinary tract infection, bacterial meningitis, and bacteremia).
However, there are a lot of pediatric practice sites where one cannot obtain a procalcitonin level timely enough to assist with decision-making.
Perhaps in response to many inquiries regarding the clinical practice guidelines, 3 pediatric emergency medicine physicians, Dr. Nathan Kuppermann from University of California-Davis, Dr. Prashant Mahajan from University of Michigan, and Dr. Peter Dayan from Columbia University have written a Pediatrics Perspectives being early released this week in Pediatrics, entitled, “Fever, Absolute Neutrophil Count, Procalcitonin and the AAP Febrile Infant Guidelines” (10.1542/peds.2022-059862). Of note, Dr. Kuppermann is an author of the 2021 guidelines.
The authors discuss the interpretation of 3 inflammatory markers: height of temperature (fever), procalcitonin level, and absolute neutrophil count (ANC). Specifically, they tackle 2 specific questions:
- How does one interpret the height of the infant’s temperature, both when a procalcitonin level is available and when it is not?
- How does one interpret the absolute neutrophil count, both when a procalcitonin level is available and when it is not?
While you should refer to this Pediatrics Perspectives for the specifics, the authors note that, if a procalcitonin level is not available, the height of fever is an important predictor for important bacterial infection, and the ANC threshold that should be used to determine high risk for important bacterial infection differs depending on the availability of the procalcitonin level.
This Pediatrics Perspectives offers practical guidance for how to proceed in the common scenario of the well-appearing febrile infant.