Febrile Neonate

• Core 1 (Pre-Clerkship)
  • Microbiology and Infectious Disease I, Week 2: Antibiotics
• Core 2 (Clerkship)
  • Pediatrics Clerkship didactics - Fever
  • Pediatric Emergency Medicine didactics - Approach to the Febrile Young Infant
• Core 3 (Post Clerkship) Electives that may further knowledge - Peds ID, Peds SubI and all Peds electives

Clinical Vignette: A 5-day old infant born at 39 weeks presents to the emergency room with fever.  

History

• Obtain details regarding fever – duration, pattern (nightly, every X hours), maximum temperature (true fever > 100.4°F or 38°C), method of measuring fever (rectal temperature considered most accurate) 

• Birth history: method of delivery, gestational age, complications during pregnancy or delivery, need for NICU stay or respiratory support, fever surrounding time of birth (did baby require a sepsis rule out while in NICU or newborn nursery?) 

• Maternal history:  

• • Infectious testing completed during pregnancy or at time of delivery (ex: testing for STIs, group B strep (GBS) and were these appropriately treated?) 

• • Maternal history of herpes simplex virus (particularly genital lesions – were any present at time of birth? Primary or secondary infection? Was mom on suppressive medications?) 

• Localizing signs of infection: cough, respiratory distress, rhinorrhea, rash, swelling, vomiting, diarrhea, or mental status changes 

• Additional history: Recent sick contacts, Oral intake/feeding tolerance 

Physical Exam

• Look for localizing signs of infection on exam to determine specific cause of fever vs fever without a source 

• Assess level of alertness, response to touch/exam, tone, and consolability 

• Need to determine if the patient is ill-appearing or well-appearing. Concerning findings for ill-appearing patient would include: 

• • Vital signs: hypotension, tachycardia, or tachypnea (based on age) 

• • Bulging or sunken fontanelle 

• • Cardiovascular: delayed capillary refill, weak or delayed femoral pulses 

• Fever in an infant 0-56 days of age is considered an emergency given increased risk for severe bacterial infection due to immature immune system. 

• If localized fever source identified: complete needed work-up (i.e. imaging, specific labs) and therapy to appropriately treat identified condition 

• • However, even if source is identified, providers will typically complete a full sepsis work-up and initiate treatment as detailed below in the evaluation and management section 

• If unable to identify source of fever: it is imperative to work-up and empirically treat for Serious Bacterial Infections (SBI, ex: urinary tract infection, meningitis/encephalitis, bacteremia) 

• See CHOP Febrile Infant Clinical Pathway for further details of workup and management 

• These recommendations are based on the AAP Febrile Neonate Guidelines last updated in 2021 

• Infants with complex medical histories and/or prematurity cannot necessarily be evaluated and managed the same as infants born at term and are otherwise healthy  

• Suggested work-up and antimicrobials are based on age and clinical appearance 

• Management differs by age due to differing levels of risk for serious bacterial infection 

• Careful consideration should be given to HSV risk factors 

• Fever in a newborn (≤56 days) is an emergency because of the immature immune system and risk for rapid systemic spread of serious bacterial infection in neonates.  

• Fever in a newborn requires different workup and empiric antimicrobial treatment based on the infant’s age as well as if the infant is well-appearing or ill-appearing.  

• Asking about birth history is important in febrile neonates, including maternal infectious history.  

• Respiratory viral testing in this age group can be used to augment decision making (particularly in infants >28 days), but there is not yet enough evidence showing that identification of a virus sufficiently lowers the risk of invasive bacterial infection to forgo further workup.  

Answers:

Q1: Ampicillin, ceftazidime, acyclovir

Q2: No

Bonus Question: Penicillin G or ampicillin given 4 hours prior to delivery 

• Articles
  • Evaluation and Management of Well-Appearing Febrile Infants 8 to 60 Days Old | Pediatrics | American Academy of Pediatrics
• Pathways
  • CHOP Febrile Infant Clinical Pathway
• Podcasts
  • #33: Febrile Infants – When Babies Are Too Hot - The Cribsiders
  • #109: Cold Chill-dren! What to do with the Hypothermic Infant
• Other Resources
  • Physical Exam findings in newborn infants (both normal and abnormal)
    • Not specific to fevers in an infant but a helpful resource for all newborn exams!