What are the diagnostic criteria and treatment options for croup?

Diagnosing and Managing Croup

Croup should be diagnosed clinically based on the characteristic barking cough and stridor, with treatment including oral corticosteroids for all cases and nebulized epinephrine for moderate to severe cases. 1, 2

Diagnostic Criteria

• Croup presents with a sudden onset of respiratory distress characterized by barking cough, stridor, and various degrees of respiratory distress, typically without antecedent cough or congestion 1, 3
• The diagnosis is primarily clinical, with radiographic studies generally unnecessary unless there is concern for an alternative diagnosis 1, 4
• Severity assessment is based on:
  • Mild: Barking cough without stridor at rest or retractions
  • Moderate: Stridor at rest with mild to moderate retractions
  • Severe: Prominent stridor with marked retractions and respiratory distress 2, 5
• Laboratory studies including viral cultures and rapid antigen testing have minimal impact on management and are not routinely recommended 4

Treatment Algorithm

For All Patients with Croup (Regardless of Severity)

• Administer a single dose of oral dexamethasone (0.15-0.6 mg/kg) 1, 3
• Alternative: Nebulized budesonide (2 mg) for children who cannot tolerate oral dexamethasone 5
• Humidification therapy (cool mist) has not been proven beneficial and is not recommended 3, 6

For Moderate to Severe Croup (Stridor at Rest or Respiratory Distress)

• Add nebulized epinephrine (0.5 ml/kg of 1:1000 solution, maximum 5 ml) 1, 2
• The effect of nebulized epinephrine is short-lived (1-2 hours), requiring close monitoring 2
• Oxygen therapy should be administered to maintain oxygen saturation ≥94% 1
• Monitor for at least 2 hours after the last dose of nebulized epinephrine to assess for rebound symptoms 2

Hospitalization Criteria

• Consider hospital admission when three or more doses of racemic epinephrine are required 1, 2
• Implementation of this guideline can reduce hospitalization rates by 37% without increasing revisits or readmissions 1, 7
• Patients with mild croup who respond to a single dose of dexamethasone can typically be discharged home after observation 2, 4

Discharge Criteria

• Resolution of stridor at rest
• Minimal or no respiratory distress
• Adequate oral intake
• Parents able to recognize worsening symptoms and return if needed 2

Important Differential Diagnoses to Consider

• Bacterial tracheitis
• Epiglottitis
• Foreign body aspiration
• Peritonsillar abscess
• Retropharyngeal abscess
• Angioedema 1, 3, 4

Common Pitfalls to Avoid

• Discharging patients too early after nebulized epinephrine (before the 2-hour observation period) 2
• Failing to administer corticosteroids in mild cases 2, 5
• Relying on radiographic studies for diagnosis rather than clinical assessment 1, 4
• Using nebulized epinephrine in children who are shortly to be discharged or on an outpatient basis due to risk of rebound symptoms 1, 2
• Performing blind finger sweeps in cases of suspected foreign body aspiration 1

Prognosis

• Most episodes of croup are mild, with only 1-8% of patients requiring hospital admission 3
• Less than 3% of admitted patients require intubation 3
• In most children, symptoms subside quickly with resolution of the cough within two days 3, 8