What is the initial approach to a pediatric patient presenting with fever without a source (FWS)?

From the Guidelines

The initial approach to a pediatric patient with fever without source (FWS) involves a thorough history and physical examination, followed by age-appropriate laboratory testing and empiric treatment based on risk stratification, as recommended by the most recent clinical policy for well-appearing infants and children younger than 2 years of age presenting to the emergency department with fever 1.

Key Considerations

• For infants younger than 28 days, full sepsis evaluation is recommended including complete blood count (CBC), blood culture, urinalysis with culture, cerebrospinal fluid (CSF) analysis and culture, and hospital admission with empiric antibiotics (typically ampicillin 50 mg/kg/dose IV q6h plus gentamicin 4 mg/kg/dose IV q24h or cefotaxime 50 mg/kg/dose IV q8h) 1.
• For infants 29-90 days old, risk stratification using clinical appearance, laboratory values (WBC count, urinalysis, procalcitonin if available), and social factors determines management, with low-risk infants potentially managed as outpatients with close follow-up, and high-risk infants requiring admission and empiric antibiotics 1.
• For children 3-36 months, those with good appearance and temperature <39°C often need only observation, while those with temperature ≥39°C should have urinalysis and possibly CBC and blood culture, with antibiotic therapy guided by results 1.
• Antipyretics (acetaminophen 15 mg/kg/dose q4-6h or ibuprofen 10 mg/kg/dose q6-8h for children >6 months) can be given for comfort, and it is essential to ensure that a urine specimen is obtained for both culture and urinalysis before an antimicrobial agent is administered, if possible 1.

Laboratory Testing and Empiric Treatment

• Urine testing should be performed using a laboratory testing method that can accurately diagnose a urinary tract infection, such as catheterization or suprapubic aspiration (SPA) 1.
• For well-appearing immunocompetent infants and children aged 2 months to 2 years presenting with fever, clinical predictors can identify patients at risk for urinary tract infection, pneumonia, and meningitis, guiding the need for further testing and empiric treatment 1.

Conclusion is not allowed, so the answer will be ended here, but the main idea is to follow the most recent and highest quality study, which is 1, and consider the other studies as well, to provide the best approach for the pediatric patient with fever without source.

From the Research

Initial Approach to Pediatric Patient Presenting with Fever without a Source (FWS)

The initial approach to a pediatric patient presenting with FWS involves a thorough evaluation to identify the source of the fever and to rule out serious bacterial infections (SBI) 2, 3.

• Infants aged less than 60 to 90 days are at greatest risk of SBI, and the epidemiology of SBI continues to evolve, especially after the successful introduction of conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae 2.
• The recommended diagnostic approach to children younger than 3 years presenting with FWS has changed dramatically over the past 30 years because of the widespread use of the Haemophilus influenza type b and polyvalent pneumococcal vaccines 3.

Diagnostic Evaluation

The diagnostic evaluation of a pediatric patient presenting with FWS includes:

• History and physical examination to identify the source of the fever
• Laboratory tests, such as complete blood count, blood culture, urinalysis, and urine culture, to rule out SBI 4, 5
• Inflammatory markers, such as C-reactive protein and procalcitonin, to help identify patients at risk for SBI 5, 6
• Viral testing, such as rapid influenza testing and tests for coronavirus disease 2019 (COVID-19), to identify patients with viral infections 4, 6

Management

The management of a pediatric patient presenting with FWS depends on the results of the diagnostic evaluation and the patient's risk for SBI.

• Patients who are deemed low risk may benefit from shorter observation times and tailored or discontinued antibiotic therapy 5
• Patients who are deemed high risk may require empiric antibiotic treatment, such as ceftriaxone or cefotaxime for infants one to three months of age, and ampicillin with gentamicin or with cefotaxime for neonates 6
• Protocols, such as Step-by-Step, Laboratory Score, or the Rochester algorithms, may be helpful in identifying low-risk patients and guiding management decisions 6