What is the recommended treatment for croup in a child aged 6 months to 3 years, including corticosteroid dosing (dexamethasone) and the use of nebulized epinephrine for moderate‑to‑severe disease?

Treatment of Croup in Children

All children with croup, regardless of severity, should receive a single dose of oral dexamethasone 0.15-0.6 mg/kg (maximum 12 mg), with nebulized epinephrine (0.5 mL/kg of 1:1000 solution, maximum 5 mL) reserved exclusively for moderate-to-severe cases requiring at least 2 hours of post-treatment observation before any consideration of discharge. 1, 2

Corticosteroid Therapy: Universal First-Line Treatment

• Administer oral dexamethasone to every child with croup, even mild cases, as corticosteroids reduce symptom intensity regardless of initial severity 1, 3
• The effective dose range is 0.15-0.6 mg/kg (maximum 12 mg), with 0.15 mg/kg proven equally effective as 0.6 mg/kg for moderate-to-severe croup 4
• For children unable to tolerate oral medication, nebulized budesonide 500-2000 µg provides equivalent efficacy within the first 2 hours 1, 3
• A single dose is sufficient; no evidence supports multi-day regimens for uncomplicated viral croup 5

Key Evidence: A randomized trial of 41 hospitalized children demonstrated no difference in croup score reduction between 0.15 mg/kg and 0.6 mg/kg dexamethasone, with median time to clinical improvement of approximately 8 hours in both groups 4. This supports using the lower dose to minimize corticosteroid exposure while maintaining efficacy.

Severity-Based Treatment Algorithm

Mild Croup (Stridor Only When Agitated, No Retractions)

• Give oral dexamethasone 0.15-0.6 mg/kg 1, 3
• Observe for 2-3 hours to ensure symptom improvement 1
• No nebulized treatments required 1
• Discharge with return precautions if stridor resolves at rest and child maintains adequate oral intake 1

Moderate-to-Severe Croup (Stridor at Rest, Retractions, Respiratory Distress)

• Immediately administer both:
  • Oral dexamethasone 0.15-0.6 mg/kg 1, 2
  • Nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) 6, 1
• Never use epinephrine without concurrent corticosteroids 2
• Recent evidence suggests 0.1 mg/kg epinephrine may be non-inferior to 0.5 mg/kg, though 0.5 mg/kg remains the established standard 7

Critical Observation and Monitoring Requirements

• Epinephrine effects last only 1-2 hours with significant rebound risk 6, 1, 2
• Mandatory minimum 2-hour observation period after the last epinephrine dose before considering discharge 1, 2
• Never discharge patients within 2 hours of epinephrine administration 1, 2
• Never use epinephrine in outpatient settings where immediate return is not feasible 6, 2

Hospitalization Criteria

• Three or more doses of nebulized epinephrine required (limiting admission to 3 doses reduces hospitalization by 37% without increasing adverse outcomes) 1
• Persistent stridor at rest despite treatment 1
• Inadequate oral intake or signs of dehydration 1
• Concerns about caregiver ability to recognize worsening symptoms 1

Discharge Criteria (All Must Be Met)

• Resolution of stridor at rest 1
• Minimal or no respiratory distress 1
• Adequate oral intake 1
• At least 2 hours elapsed since last epinephrine dose with no symptom rebound 1, 2
• Parents able to recognize worsening symptoms and understand return precautions 1

Common Pitfalls to Avoid

• Failing to give corticosteroids in mild cases – even mild croup benefits from dexamethasone 1, 3
• Discharging patients before the 2-hour post-epinephrine observation window – this is the highest-risk error given rebound potential 1, 2
• Using epinephrine as monotherapy without corticosteroids – always give both concurrently in moderate-to-severe cases 2
• Prescribing normal saline nebulization – no evidence supports this practice for croup treatment 1, 2
• Failing to provide clear return precautions – parents must understand when to seek immediate re-evaluation 1

Ineffective Interventions

• Normal saline nebulization has no role in croup management 1, 2
• Cool mist therapy lacks supporting evidence 3
• Antihistamines, decongestants, and antibiotics have no proven benefit in uncomplicated viral croup 5