What is the recommended treatment for croup in children aged 6 months to 3 years, including corticosteroid dosing and indications for adding nebulized epinephrine?

Treatment of Croup in Children

Administer oral dexamethasone 0.15-0.6 mg/kg (maximum 10-12 mg) as a single dose to ALL children with croup, regardless of severity, and reserve nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) for moderate to severe cases with stridor at rest or significant respiratory distress. 1

First-Line Treatment: Corticosteroids for All Cases

• Oral dexamethasone is the gold standard for croup treatment at any severity level 1
• The recommended dose range is 0.15-0.6 mg/kg as a single dose, with a maximum of 10-12 mg 1
• Research confirms that 0.15 mg/kg is equally effective as 0.6 mg/kg for moderate to severe croup, with no difference in croup score reduction at any time point 2
• The lower dose (0.15 mg/kg) may be preferred to minimize steroid exposure while maintaining efficacy 2
• Onset of action is approximately 6 hours after administration, so symptoms may not improve immediately 3

Alternative Corticosteroid Options

• Nebulized budesonide 500-2000 µg reduces symptoms within the first 2 hours and has equivalent efficacy to oral dexamethasone 4
• Intramuscular dexamethasone 0.6 mg/kg is appropriate for children who cannot tolerate oral medication 3, 5

When to Add Nebulized Epinephrine

Reserve nebulized epinephrine for moderate to severe croup only, defined by: 1, 5

• Stridor at rest (not just with agitation or crying)
• Significant respiratory distress with accessory muscle use
• Respiratory rate >70 breaths/min in infants
• Oxygen saturation <92%

Epinephrine Dosing

• Standard dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) via nebulizer 1
• Recent evidence shows 0.1 mg/kg is non-inferior to 0.5 mg/kg for moderate to severe croup, though the higher dose remains standard 6
• The traditional racemic epinephrine dose is 0.5 mL of 2.25% solution diluted in 2.5 mL saline 7
• Effect lasts only 1-2 hours, requiring close monitoring for rebound symptoms 4, 3

Critical Observation Requirements After Epinephrine

• Mandatory observation for at least 2 hours after the last epinephrine dose to monitor for rebound airway obstruction 1, 4, 3
• Never discharge within 2 hours of epinephrine administration 1
• Never use epinephrine in outpatient settings where immediate return is not feasible 1, 4

Hospitalization Criteria

Admit patients who meet any of the following: 1

• Require ≥3 doses of nebulized epinephrine
• Oxygen saturation <92%
• Age <18 months
• Respiratory rate >70 breaths/min
• Persistent respiratory distress despite treatment
• Persistent stridor at rest after treatment 4

Important Hospitalization Nuance

• Do not admit after only 1-2 doses of epinephrine if a third dose could be safely administered in the emergency department, as this unnecessarily increases hospitalization rates 1
• The threshold of 3 doses can reduce hospitalization rates by 37% without increasing revisits or readmissions 4

Treatment Algorithm by Severity

Mild Croup (No Stridor at Rest)

• Oral dexamethasone 0.15-0.6 mg/kg alone 1
• Observation for 2-3 hours to ensure symptoms are improving 4
• No nebulized treatments needed 4

Moderate to Severe Croup (Stridor at Rest)

• Oral dexamethasone 0.15-0.6 mg/kg PLUS nebulized epinephrine 0.5 mL/kg of 1:1000 solution 1
• Administer epinephrine immediately while waiting for dexamethasone to take effect (6-hour onset) 3, 5
• Simultaneous administration reduces intubation rates in severe croup with impending respiratory failure 5
• Observation for minimum 2 hours after last epinephrine dose 1, 4

Discharge Criteria

Patients may be discharged when ALL of the following are met: 4

• Resolution of stridor at rest
• Minimal or no respiratory distress
• Adequate oral intake
• At least 2 hours have passed since last epinephrine dose
• Parents can recognize worsening symptoms and understand return precautions

Common Pitfalls to Avoid

• Never rely on cool mist therapy as definitive treatment—it lacks evidence of benefit 1
• Never use antibiotics routinely—croup is viral in etiology 1, 7
• Never discharge too early after nebulized epinephrine (before 2-hour observation) 4
• Never fail to administer corticosteroids even in mild cases 4
• Never withhold dexamethasone thinking the case is "too mild"—early intervention reduces return visits and hospital admissions 5
• Never use lower steroid doses than 0.15 mg/kg, as they have proven ineffective 3

Supportive Care

• Maintain at least 50% relative humidity in the child's room 3
• Ensure adequate hydration 7
• Provide fever control as needed 7
• Avoid agitation—crying and distress worsen airway obstruction 3
• Antihistamines and decongestants have no proven effect on viral croup 7