What are the classifications and treatment options for croup?

Classification of Croup

Severity Classification

Croup is classified into mild, moderate, and severe categories based on the presence and severity of stridor and respiratory distress, which directly determines treatment approach. 1

Mild Croup

• Stridor present only with agitation or activity 2
• No stridor at rest 1
• Absent or minimal intercostal retractions 2
• Barking cough and hoarse voice present 3, 4
• Child appears comfortable when calm 4

Moderate Croup

• Stridor audible at rest 2
• Intercostal retractions present with increased work of breathing 2
• No signs of severe respiratory distress or impending respiratory failure 1
• Child may appear anxious but not agitated 5

Severe/Life-Threatening Croup

• Stridor at rest with significant respiratory distress 6
• Marked intercostal, subcostal, or sternal retractions 5
• Agitation, restlessness, or obvious distress indicating potential airway obstruction 5
• Oxygen saturation <92% 1
• Respiratory rate >70 breaths/min 1
• Lethargy or decreased level of consciousness 5

Treatment Algorithm by Severity

Mild Croup

Administer oral dexamethasone 0.15-0.6 mg/kg (maximum 10-12 mg) as a single dose—this is sufficient treatment without nebulized epinephrine. 1, 2

• Observe for 2-3 hours to ensure symptoms are improving 6
• No nebulized treatments required 6
• Prednisolone 1.0 mg/kg is an alternative oral corticosteroid 5, 4

Moderate to Severe Croup

Add nebulized epinephrine (0.5 ml/kg of 1:1000 solution, maximum 5 ml) to oral dexamethasone. 1, 6

• Administer oral dexamethasone 0.15-0.6 mg/kg first 1
• Give nebulized epinephrine for immediate symptom relief 1, 2
• Observe for at least 2 hours after the last epinephrine dose due to short-lived effect (1-2 hours) and risk of rebound symptoms 6, 7
• Nebulized budesonide 2 mg is equally effective as oral dexamethasone when oral administration is not feasible 1, 2, 8
• Provide supplemental oxygen to maintain saturation ≥94% 1, 5

Hospitalization Criteria

Consider hospital admission after 3 doses of nebulized epinephrine rather than the traditional 2 doses—this approach reduces hospitalization rates by 37% without increasing adverse outcomes. 1, 6

Additional admission criteria include:

• Oxygen saturation <92% 1
• Age <18 months 1
• Respiratory rate >70 breaths/min 1
• Persistent difficulty breathing despite treatment 1
• Persistent stridor at rest after treatment 6

Discharge Criteria

Patients may be discharged when:

• Resolution of stridor at rest 1, 6
• Minimal or no respiratory distress 1, 6
• Adequate oral intake 1, 6
• Parents able to recognize worsening symptoms and know when to return 1, 6
• At least 2 hours have passed since last epinephrine dose without symptom rebound 6

Critical Pitfalls to Avoid

Never discharge patients before the 2-hour observation period after nebulized epinephrine administration—this is the most common and dangerous error. 1, 6

• Do not use nebulized epinephrine in outpatient settings where adequate observation is not possible 1, 6
• Do not withhold corticosteroids in mild cases—all severity levels benefit from steroids 1, 6
• Do not admit after only 1-2 doses of epinephrine when a third dose could be safely administered in the emergency department 1
• Do not routinely use antibiotics—croup is viral in etiology 1
• Do not rely on cold air or humidified air treatments—these lack evidence of benefit 1
• Do not perform radiographic studies routinely—diagnosis is clinical unless alternative diagnosis is suspected 1, 5
• Ensure clear return precautions are provided to parents 1, 6

Alternative Diagnoses to Consider

When croup fails to respond to standard treatment after 3 doses of epinephrine, consider:

• Bacterial tracheitis 5, 3
• Foreign body aspiration 5, 3
• Epiglottitis 3, 7
• Retropharyngeal abscess 3, 7
• Peritonsillar abscess 3
• Angioedema 3

Proceed to direct laryngoscopy and bronchoscopy when standard treatment fails to identify the true pathology. 5