Febrile Infant

Infant

Age (days)

Weight (kg), for doses

Does the guideline apply?

All must be true:

Well-appearing (clinician confident) Temperature ≥ 38.0°C (100.4°F), rectal, at home in the past 24 hours or in clinic (needn't be febrile now) Born at 37 to under 42 weeks

Exclusions: tick any that apply

Circumcised boy (29–60 days: UTI risk under 1%, may skip the UA)

HSV

Obtain HSV studies and start acyclovir if any are present:

Results

Procalcitonin available (timely)?

Yes No

Procalcitonin (ng/mL)

ANC (cells/mm³)

Urinalysis

Negative PositiveAny leukocyte esterase, > 5 WBC/hpf (centrifuged) or > 10 WBC/mm³ (uncentrifuged)

CSF

Not obtained Normal Enterovirus +Otherwise reassuring Suggests bacterial meningitis

CSF WBC (cells/mm³), optional

Febrile Infant 8–60 Days

Infant

Does the guideline apply?

HSV

Results

Urinalysis

CSF

Plan