What is the differential diagnosis (ddx) and management for a 2-year-old child with low-grade fever, cough, and eye discharge?

Differential Diagnosis and Management of a 2-Year-Old with Low-Grade Fever, Cough, and Eye Discharge

The most likely diagnosis is viral upper respiratory infection with conjunctivitis, which should be managed with supportive care and close observation, but you must actively rule out acute bacterial sinusitis, pneumonia, and urinary tract infection based on specific clinical criteria. 1, 2

Differential Diagnosis

Primary Considerations

Viral Upper Respiratory Infection with Viral Conjunctivitis

• Most common cause in this age group, typically self-limiting 2, 3
• Eye discharge is usually watery or mucoid, bilateral, and associated with nasal symptoms 2

Acute Bacterial Sinusitis

• Diagnose if the child has persistent illness (nasal discharge of any quality or daytime cough lasting >10 days without improvement) 4
• Or worsening course (new or worsening nasal discharge, cough, or fever after initial improvement) 4
• Or severe onset (fever ≥39°C/102.2°F with purulent nasal discharge for ≥3 consecutive days) 4

Community-Acquired Pneumonia

• Consider if tachycardia is out of proportion to fever, especially with fever ≥39°C, cough, or hypoxia 1
• The combination of tachycardia, tachypnea, cough, hypoxia, rales, high fever, and fever duration >48 hours has 94% sensitivity for radiographic pneumonia 1

Urinary Tract Infection

• Accounts for >90% of serious bacterial infections in children aged 2 months to 2 years 1
• Consider especially in females, fever duration >24 hours, or temperature ≥39°C 2

Less Common but Important

Measles

• Classic triad: cough, conjunctivitis (with eye discharge), and coryza with fever 2
• Check immunization status 2

Management Algorithm

Step 1: Initial Assessment

Document vital signs and clinical appearance 4, 2

• Measure rectal temperature (fever = ≥38.0°C/100.4°F) 4, 1
• Assess for toxic appearance, respiratory distress, altered consciousness, or signs of shock 4, 2
• Check respiratory rate, heart rate, and oxygen saturation 1

Determine illness duration and pattern 4

• If symptoms <10 days and stable/improving: likely viral URI 4
• If symptoms >10 days without improvement: consider bacterial sinusitis 4
• If initially improved then worsened: consider bacterial sinusitis 4

Step 2: Targeted Evaluation Based on Clinical Findings

If respiratory symptoms predominate:

• Obtain chest radiograph if tachycardia out of proportion to fever, fever ≥39°C, hypoxia, or rales present 1
• Do NOT obtain chest radiograph if wheezing or bronchiolitis is likely 1, 2

If fever persists or child appears more ill than expected:

• Obtain urinalysis with leukocyte esterase, nitrites, and microscopy via catheterization (preferred over clean catch due to lower contamination: 12% vs 26%) 1, 2
• Obtain urine culture before starting antibiotics if urinalysis is positive 1

If sinusitis criteria met (persistent, worsening, or severe):

• Clinical diagnosis only—do NOT obtain imaging studies (plain radiography, CT, MRI, or ultrasound) to distinguish bacterial sinusitis from viral URI 4

Step 3: Treatment Decisions

For Acute Bacterial Sinusitis:

• Severe or worsening course: Prescribe antibiotics immediately 4
• Persistent illness: Either prescribe antibiotics OR offer additional observation for 3 days before treating 4
• First-line antibiotic: Amoxicillin with or without clavulanate 4
• If vomiting or unable to take oral medications: Ceftriaxone 50 mg/kg IV/IM once, then switch to oral therapy after clinical improvement 4
• Penicillin allergy: Cefdinir, cefuroxime, or cefpodoxime 4
• Reassess at 72 hours if no improvement or worsening 4

For Pneumonia (if identified on chest radiograph):

• Initiate appropriate antibiotic therapy based on radiographic findings and clinical severity 1
• Consider admission if respiratory distress, hypoxia, or inability to maintain oral hydration 1

For UTI (if urinalysis positive):

• Start ceftriaxone 50 mg/kg IV/IM daily 1
• Ensure urine culture obtained before antibiotics 1

For Eye Discharge:

• If bacterial conjunctivitis suspected (purulent discharge): Erythromycin ophthalmic ointment approximately 1 cm applied to infected eye(s) up to 6 times daily 5
• If viral conjunctivitis (watery/mucoid discharge): Supportive care only 2

For Fever Management:

• Treat for comfort, not to normalize temperature 3
• Acetaminophen (paracetamol) is first-line antipyretic 6, 3
• Ensure adequate fluid intake 6
• Avoid physical cooling methods (tepid sponging, cold bathing) as they cause discomfort 6

Step 4: Red Flags Requiring Immediate Intervention

Instruct parents to return immediately if: 1, 2

• Altered consciousness or severe lethargy
• Respiratory distress (markedly raised respiratory rate, grunting, intercostal recession)
• Cyanosis
• Signs of dehydration or persistent vomiting
• Petechial or purpuric rash
• Fever persisting ≥5 days (evaluate for Kawasaki disease) 6
• Severe headache, photophobia, or seizures 4
• Eye swelling with proptosis or impaired extraocular muscle function (orbital complications) 4

Common Pitfalls to Avoid

Do not obtain imaging for uncomplicated sinusitis 4

• Imaging does not contribute to diagnosis and is unnecessary 4
• Reserve contrast-enhanced CT for suspected orbital or CNS complications only 4

Do not rely solely on clinical appearance 2

• Only 58% of infants with bacteremia or bacterial meningitis appear clinically ill 4, 2

Do not use trimethoprim/sulfamethoxazole or azithromycin for sinusitis 4

• Surveillance studies show resistance of pneumococcus and H. influenzae to these agents 4

Do not use bag specimens for urine collection 1, 2

• Catheterization has significantly lower contamination rates 1, 2