Approach to Fever in Children: Diagnostic Evaluation & Management Tool

Clinical History Assessment

Systematic approach to history taking for a child presenting with fever

Physical Examination Guide

Systematic approach to examining a child with fever

Diagnostic Approach

Initial Assessment

For a child presenting with fever, the initial assessment should include:

• Detailed history focusing on duration, pattern, and associated symptoms
• Complete physical examination to identify potential source of infection
• Assessment of hydration status and overall appearance
• Risk stratification based on age and clinical presentation

Definitions and Classification of Fever

Understanding the terminology and classification of fever:

Term	Definition	Clinical Significance
Fever	Temperature ≥38.0°C (100.4°F)	Physiologic response to infection or inflammation
Low-grade fever	Temperature 38.0-38.9°C (100.4-102.0°F)	Common in viral infections, less concerning
High fever	Temperature ≥39.0°C (≥102.2°F)	Higher risk of serious bacterial infection
Fever without source (FWS)	Fever without localizing signs or symptoms after history and physical examination	Requires age-appropriate risk assessment
Persistent fever	Fever lasting >3 days	Higher risk of bacterial infection
Fever of unknown origin (FUO)	Fever >38.3°C (101°F) for ≥8 days without clear etiology after initial evaluation	Consider broader differential including unusual infections, malignancy, autoimmune

Age-Based Risk Stratification

Age Group	Risk Considerations	Evaluation Approach
Neonates (0-28 days)	- Highest risk for serious bacterial infection (SBI) - Limited ability to localize infection - Subtle or minimal symptoms despite serious illness - Immature immune system	- Full sepsis evaluation (blood, urine, CSF) - Hospitalization for most - Empiric antibiotics pending cultures - Lower threshold for imaging
Young infants (29-90 days)	- Moderate risk for SBI - UTI most common SBI - Bacteremia and meningitis less common than in neonates - Low-risk criteria may apply	- Risk stratification using clinical criteria - Low-risk may be managed outpatient - Higher risk warrant full sepsis evaluation - Selective approach to lumbar puncture
Infants and toddlers (3-36 months)	- Lower risk for SBI than younger infants - UTI remains most common SBI - Occult bacteremia less common post-vaccination - Able to localize some infections	- Focused evaluation based on clinical findings - Urinalysis for most - Selective blood work based on appearance and temperature - Outpatient management for most well-appearing children
Older children (>36 months)	- Lowest risk for SBI - Usually able to localize infections - Broader differential including viral illnesses - Consider non-infectious causes	- Focused evaluation based on symptoms - Minimal laboratory testing for well-appearing - Consider throat, respiratory testing for specific symptoms - Outpatient management for most

Differential Diagnosis

System	Conditions	Red Flags
Respiratory	- Upper respiratory tract infection - Pharyngitis/tonsillitis - Otitis media - Pneumonia - Bronchiolitis	- Respiratory distress - Hypoxemia - Significant chest retractions - Grunting - Tachypnea out of proportion to fever
Gastrointestinal	- Gastroenteritis - Appendicitis - Hepatitis - Peritonitis - Cholecystitis	- Severe abdominal pain - Bilious vomiting - Bloody diarrhea - Abdominal rigidity - Jaundice
Genitourinary	- Urinary tract infection - Pyelonephritis - Epididymitis - Pelvic inflammatory disease	- Costovertebral angle tenderness - Oliguria/anuria - Testicular pain/swelling - Vaginal discharge - Lower abdominal pain
Central Nervous System	- Meningitis - Encephalitis - Brain abscess - Intracranial empyema	- Altered mental status - Neck stiffness - Bulging fontanelle - Seizures - Focal neurological signs
Skin/Soft Tissue	- Cellulitis - Abscess - Impetigo - Lymphadenitis - Osteomyelitis	- Rapidly spreading erythema - Significant swelling - Fluctuance - Limited range of motion - Point tenderness over bone
Systemic	- Bacteremia - Sepsis - Kawasaki disease - Juvenile idiopathic arthritis - Malignancy	- Petechiae/purpura - Poor perfusion - Persistent fever >5 days - Persistent lymphadenopathy - Hepatosplenomegaly

Laboratory Studies

Consider these studies based on age, clinical presentation, and risk factors:

Investigation	Clinical Utility	When to Consider
Complete Blood Count (CBC)	Assess for leukocytosis, leukopenia, or thrombocytopenia	High fever, ill-appearing, age <3 months, persistent fever
Blood Culture	Identify bacteremia	Age <3 months, toxic appearance, immunocompromised, high fever ≥39°C
Urinalysis/Urine Culture	Identify urinary tract infection	Age <24 months with fever without source, dysuria, frequency, abdominal pain
Cerebrospinal Fluid (CSF) Analysis	Evaluate for meningitis/encephalitis	Age <1 month, altered mental status, neck stiffness, immunocompromised
C-Reactive Protein (CRP)/Procalcitonin	Markers of inflammation, help differentiate viral vs. bacterial	Fever without source, risk stratification, monitoring response to treatment
Rapid Antigen Testing	Identify specific pathogens (Strep, Influenza, RSV)	Specific symptoms suggesting these infections
Chest X-ray	Evaluate for pneumonia	Respiratory symptoms, tachypnea, abnormal lung exam, persistent fever

Diagnostic Algorithm

A stepwise approach to diagnosing fever in children:

1. Determine patient age and risk factors (including immunization status)
2. Assess clinical appearance (well vs. ill-appearing)
3. Perform targeted history and physical examination to identify potential source
4. Stratify risk based on age, appearance, and clinical findings
5. Select appropriate laboratory and imaging studies based on risk stratification
6. Consider empiric treatment based on age and clinical presentation
7. Determine appropriate disposition (home vs. observation vs. admission)
8. Arrange follow-up to ensure resolution and monitor for complications

Management Strategies

General Approach to Management

Key principles in managing fever in children:

• Treat the patient, not the number: Focus on overall clinical appearance and comfort
• Identify and treat underlying cause: Address the source of fever when possible
• Provide supportive care: Ensure adequate hydration and comfort measures
• Antipyretics for comfort: Use when child is uncomfortable, not just to normalize temperature
• Patient education: Address misconceptions about fever and provide guidance on home management
• Clear return precautions: Ensure caregivers understand when to seek further care

Supportive Care

Intervention	Description	Evidence and Recommendations
Hydration	- Encourage oral fluid intake - Offer small amounts frequently - Consider sports drinks for older children - Monitor urine output	- Strong evidence for maintaining hydration - Increased fluid needs during fever (↑ 12% per 1°C) - IV fluids only if unable to maintain oral intake - Consider ORS for children with gastroenteritis
Physical Cooling Methods	- Light clothing - Comfortable room temperature - Tepid sponging if temperature very high	- Limited evidence for effectiveness - Avoid alcohol baths or ice packs - May cause shivering which can increase temperature - Not recommended as primary intervention
Rest	- Encourage adequate sleep - Quiet activities during waking hours - Avoid excessive exertion	- Expert consensus supports rest during fever - Allow child to determine activity level - No need to enforce bed rest if child feels active
Nutrition	- Offer regular meals - Focus on easily digestible foods - Follow child's appetite	- No evidence that "starving a fever" is beneficial - Decreased appetite common during fever - Focus on hydration if appetite poor

Pharmacological Management

Medication	Dosing	Evidence and Considerations
Acetaminophen (Paracetamol)	- 10-15 mg/kg/dose every 4-6 hours - Maximum 5 doses in 24 hours - Maximum daily dose: 75 mg/kg/day, not to exceed 4000 mg/day	- First-line antipyretic - Effective for both fever and pain - Less risk of gastrointestinal side effects than NSAIDs - Available in multiple formulations - Risk of hepatotoxicity with overdose
Ibuprofen	- 5-10 mg/kg/dose every 6-8 hours - Maximum 4 doses in 24 hours - Maximum daily dose: 40 mg/kg/day, not to exceed 2400 mg/day - Not recommended under 6 months of age	- Effective alternative to acetaminophen - May provide longer duration of effect - Avoid in dehydration or kidney disease - Risk of gastrointestinal irritation - Controversial in chickenpox (theoretical risk of severe skin infections)
Alternating Antipyretics	- Use acetaminophen and ibuprofen on staggered schedule - Recommended only for persistent high fever with discomfort	- Some evidence for enhanced temperature control - Increased risk of dosing errors - May promote fever phobia - Not routinely recommended
Aspirin	- Not recommended for children and adolescents	- Associated with Reye syndrome in children with viral illnesses - Exception: Specific conditions like Kawasaki disease under physician guidance

Antibiotic Therapy

Clinical Scenario	Approach	Common Antibiotics
Fever without source (FWS) in neonates (0-28 days)	- Empiric antibiotics after full sepsis workup - Hospitalization recommended - Broad-spectrum coverage	- Ampicillin + gentamicin OR - Ampicillin + cefotaxime - Consider acyclovir if HSV suspected
FWS in young infants (29-90 days)	- Risk stratification (low vs. high risk) - High risk: similar to neonates - Low risk: may observe or treat with close follow-up	- Ceftriaxone for high-risk or outpatient management - Ampicillin + gentamicin/cefotaxime for inpatient
FWS in older infants/children (>3 months)	- Generally observe well-appearing children - Consider antibiotics if high fever (≥39°C), elevated inflammatory markers, or not fully immunized	- Ceftriaxone if antibiotics deemed necessary - Alternatives based on local resistance patterns
Urinary tract infection	- Empiric antibiotics after urinalysis/culture - Consider parenteral for toxic appearance or young infants - Oral for most uncomplicated cases	- Oral: Cephalexin, amoxicillin-clavulanate, TMP-SMX - Parenteral: Ceftriaxone, ampicillin + gentamicin
Pneumonia	- Base therapy on clinical presentation, age, and local epidemiology - Consider viral etiology in young children - Empiric coverage for typical and atypical pathogens	- Outpatient: Amoxicillin, amoxicillin-clavulanate, macrolide (if atypical suspected) - Inpatient: Ampicillin, ceftriaxone ± macrolide

Management of Specific Conditions

Condition	Key Management Points	Follow-up Recommendations
Otitis Media	- Pain management with acetaminophen/ibuprofen - Antibiotics for severe cases, bilateral disease, or age <2 years - Consider watch-and-wait approach for mild cases in older children	- Follow-up in 48-72 hours if watchful waiting - Re-evaluate if symptoms worsen - Consider tympanometry at resolution
Pharyngitis	- Test for Group A Streptococcus if clinical suspicion - Treat with antibiotics if positive - Supportive care for viral pharyngitis	- Follow-up if symptoms persist >72 hours - No routine follow-up testing needed - Educate about completion of antibiotic course
Viral Exanthems	- Supportive care and antipyretics - Isolation precautions as appropriate - Specific management for certain viruses (e.g., acyclovir for severe HSV)	- Follow-up if fever persists beyond expected duration - Most resolve without specific treatment - Return if new symptoms develop
Febrile Seizures	- Seizure safety measures - Antipyretics for comfort, not prevention of seizures - Education and reassurance for parents	- Follow-up with primary care provider - Neurology referral for complex febrile seizures - Educate about recurrence risk
Kawasaki Disease	- High-dose aspirin - Intravenous immunoglobulin (IVIG) - Cardiac evaluation and monitoring	- Cardiology follow-up - Echocardiograms at diagnosis, 2 weeks, and 6-8 weeks - Long-term management based on coronary artery findings

Disposition and Follow-up

Disposition Decision	Criteria	Management Plan
Discharge Home	- Well-appearing - Age >3 months (or >28 days if low risk) - No concerning features - Reliable caregivers with access to follow-up	- Clear discharge instructions - Return precautions - Antipyretics as needed - Follow-up within 24-48 hours if fever persists
Observation	- Borderline appearance - Age 29-90 days with reassuring initial workup - Clinical uncertainty requiring extended monitoring	- 6-24 hours of observation - Serial assessments - Consider limited empiric antibiotics - Discharge if improved, admit if worsening
Admission	- Age <28 days with fever - Toxic appearance - Suspected serious bacterial infection - Dehydration requiring IV fluids - Immunocompromised	- Appropriate empiric antibiotics - Supportive care - Ongoing monitoring - Specialist consultation as needed
Intensive Care	- Hemodynamic instability - Respiratory failure - Altered mental status - Signs of septic shock	- Aggressive fluid resuscitation - Vasoactive support if needed - Broad-spectrum antibiotics - Mechanical ventilation if required - Continuous monitoring

Parent Education and Return Precautions

• Education on fever: Explain fever as a protective mechanism, not an illness itself
• Fever management at home: Hydration, appropriate antipyretics, comfort measures
• Return precautions: When to seek immediate medical attention
• Infant <3 months with recurrent fever
• Lethargy or decreased responsiveness
• Difficulty breathing
• Persistent vomiting or inability to keep fluids down
• Rash that doesn't blanch with pressure
• Persistent pain or irritability despite antipyretics
• Fever lasting >5 days
• Seizure
• Signs of dehydration (dry mouth, decreased urination, no tears)
• Maintaining hydration: Signs of adequate fluid intake and dehydration warning signs
• Appropriate use of antipyretics: Dosing, timing, and avoiding overtreatment
• Dispelling fever myths: Address common misconceptions about fever and its management