Initial approach to the infant younger than 2 months of age who presents with fever

Area of Science:

• Pediatrics
• Infectious Diseases
• Neonatology

Background:

• Fever is a common symptom in infants, particularly those under two months.
• Infants younger than two months have immature immune systems, increasing their susceptibility to serious bacterial infections (SBI).
• Common bacterial pathogens include E. coli, group B Streptococcus, L. monocytogenes, Pneumococcus, Neisseria meningitidis, S. aureus, and H. influenzae.

Purpose of the Study:

• To identify clinical characteristics associated with an increased risk of SBI in febrile infants.
• To guide the evaluation and management of febrile infants younger than two months.
• To differentiate between infants requiring hospitalization and those suitable for outpatient management.

Main Methods:

• Review of clinical characteristics and laboratory findings in febrile infants.
• Assessment of risk factors for SBI, including age, appearance, and diagnostic test results.
• Evaluation of the role of clinical judgment and fever severity in diagnosing SBI.

Main Results:

• Ill-appearing infants, those with abnormal hemograms or urinalyses, or physical signs of bacterial infection are at higher risk for SBI.
• The association between high fever and SBI is inconclusive.
• Clinical judgment is important but not always reliable in ruling out SBI.

Conclusions:

• Young infants with fever require thorough evaluation including history, physical examination, and laboratory studies.
• Infants younger than 29 days typically require admission for observation and parenteral antibiotics.
• Infants aged 29-60 days may be managed as outpatients after careful evaluation, potentially with antibiotics.