How should I manage an 11‑month‑old infant presenting with fever and vomiting?

Management of an 11-Month-Old with Fever and Vomiting

For an 11-month-old infant presenting with fever and vomiting, obtain a catheterized urine specimen for culture immediately, assess hydration status and oxygen saturation, and determine whether the child appears well or ill to guide the need for hospitalization and empiric antibiotics. 1

Immediate Assessment Priorities

Vital Signs and Clinical Appearance

• Measure rectal temperature to confirm fever ≥38°C (100.4°F), as other methods are unreliable in infants 1
• Check oxygen saturation; ≤92% is an absolute indication for hospitalization 1, 2
• Assess for signs of serious bacterial infection: cyanosis, poor peripheral circulation, petechial rash, inconsolability, or toxic appearance 3
• Evaluate hydration status by checking mucous membranes, capillary refill, urine output, and skin turgor 1

Key Physical Examination Findings

• Look for respiratory signs: cough, hypoxia, wheezing, rales, or disproportionate tachypnea 1
• Examine for meningeal signs: altered mental status, focal neurologic deficits, or severe irritability 1
• Assess for dehydration severity: sunken fontanelle, decreased tears, dry mucous membranes 1

Diagnostic Testing

Mandatory Initial Tests

• Catheterized urine specimen for urinalysis and culture (not bag collection) is essential, as urinary tract infections account for >90% of serious bacterial illness in this age group 1, 4
• The risk of UTI increases significantly with fever ≥39°C, fever duration >24 hours, and in females 1
• Blood culture should be obtained before antibiotics if serious bacterial infection is suspected 1, 2

Conditional Testing Based on Clinical Presentation

• Chest radiography is indicated only if respiratory symptoms are present (cough, hypoxia, wheezing, rales) or fever >48 hours 1
• Do not obtain routine chest radiography in well-appearing infants without respiratory signs—the diagnostic yield is <3% 5
• Lumbar puncture is not routinely indicated in a well-appearing 11-month-old without meningeal signs or toxic appearance 1, 5
• The incidence of bacterial meningitis is significantly lower at this age compared to neonates, supporting selective rather than routine cerebrospinal fluid sampling 5

Special Consideration: Fever ≥5 Days

If fever has persisted for 5 days or longer, immediately evaluate for Kawasaki disease, which is especially common in incomplete form in infants <1 year and carries high risk of coronary artery aneurysms if untreated 1, 5

• Examine for the five principal features: bilateral conjunctival injection, oral mucosal changes (cracked lips, strawberry tongue), polymorphous rash, extremity changes (erythema/edema of hands/feet), cervical lymphadenopathy ≥1.5 cm 5
• If ≥2 features are present, obtain inflammatory markers (ESR, CRP), complete blood count, comprehensive metabolic panel, and urgent echocardiography 5
• ESR ≥40 mm/hr (often >100) and CRP ≥3 mg/dL support the diagnosis 5

Management Algorithm

Well-Appearing Infant (No Toxic Signs)

• Obtain catheterized urine for culture 1
• Consider blood culture if clinical concern for bacteremia exists 1
• Administer acetaminophen or ibuprofen only if fever causes discomfort 1
• Do not use combined or alternating antipyretics 1
• Ensure adequate hydration; consider oral rehydration solution if mild dehydration present 1

Ill-Appearing or Toxic Infant

• Obtain blood culture, catheterized urine culture, and consider lumbar puncture 1, 3
• Initiate empiric antibiotics immediately after cultures: ceftriaxone or cefotaxime are appropriate for this age 3
• Hospitalize for intravenous antibiotics and close monitoring 1

Disposition Criteria

Safe for Discharge (All Must Be Met)

• Well-appearing clinical status 1
• All laboratory investigations negative or appropriately managed 1
• Normal oxygen saturation 1
• Adequate hydration 1
• Reliable caregivers with verbal and written instructions 1
• Guaranteed follow-up within 24 hours 1
• Clear return precautions provided 1

Indications for Hospitalization

• Toxic or severely ill appearance 1
• Oxygen saturation ≤92% 1, 2
• Severe dehydration 1
• Inability to tolerate oral fluids due to persistent vomiting 1
• Suspected serious bacterial infection requiring parenteral antibiotics 1

Parent Education and Safety-Netting

Return Immediately If:

• Recurrence or worsening of vomiting with inability to keep fluids down 2
• Development of altered consciousness, severe lethargy, or inconsolability 2
• Respiratory distress, rapid or labored breathing, or cyanosis 2
• Signs of dehydration: decreased urine output, sunken fontanelle, no tears 1
• Fever persisting ≥5 days (evaluate for Kawasaki disease) 1, 5
• Petechial or purpuric rash 2
• New concerning symptoms: conjunctival redness, lip cracking, swelling of hands/feet, neck swelling 5

Follow-Up Instructions

• Reassess within 24-48 hours if fever persists, even if initial tests were negative 1
• Ensure urine testing with subsequent febrile illnesses, as UTI presentations can be delayed 1
• Do not rely on response to antipyretics as an indicator of disease severity—this is not a reliable predictor of serious bacterial infection 6, 1

Common Pitfalls to Avoid

• Do not use bag-collected urine specimens for diagnosis—contamination rates are too high; only catheterized specimens are acceptable 1
• Do not assume normal urinalysis excludes UTI—obtain culture if clinical risk factors are present (fever ≥39°C, duration >24 hours, female sex) 1
• Do not ignore the possibility of Kawasaki disease in infants with prolonged fever, even without classic features—incomplete presentation is common at this age 1, 5
• Do not perform routine lumbar puncture in well-appearing 11-month-olds without specific indications—this differs from neonatal management 1, 5
• Do not obtain chest radiography routinely in the absence of respiratory symptoms 1, 5