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PECARN rule for low-risk febrile infants 8-60 days old

Rules out serious bacterial infection using UA, ANC, and procalcitonin.

PECARN rule for low-risk febrile infants 8-60 days old
Urinalysis positive for pyuria (leukocyte esterase or nitrite positive, or >5 WBC/hpf)
Absolute neutrophil count (ANC)
/µL
Procalcitonin
ng/mL
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When to use

  • Well-appearing, term febrile infants 8-60 days old being risk-stratified for serious bacterial infection (UTI, bacteremia, bacterial meningitis).

Formula

Low risk if urinalysis is negative for pyuria AND ANC <=4,090/µL AND procalcitonin <=1.71 ng/mL.

Pearls and pitfalls

  • Derived/validated in well-appearing infants without a focal bacterial infection other than possible UTI — not for ill-appearing infants.
  • A positive urinalysis does not exclude concurrent bacteremia; blood culture is still generally indicated.

References

  1. Kuppermann N, Dayan PS, Levine DA, et al. JAMA Pediatr. 2019;173(4):342-351.