Treatment of Severe Croup with Corticosteroids
For severe croup, administer a single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) orally, intramuscularly, or intravenously, combined with nebulized epinephrine for immediate symptom relief. 1
Corticosteroid Dosing and Administration
Dexamethasone Dosing
- The standard dose is 0.6 mg/kg (maximum 16 mg) given as a single dose 1
- All three routes (oral, IM, IV) are equally effective 1
- Oral administration is preferred when the child can tolerate it, as it avoids injection pain and is equally effective as parenteral routes 1
- For children unable to take oral medication due to vomiting or severe respiratory distress, use IM or IV administration 2, 3
Lower Dose Considerations
- While 0.6 mg/kg is the standard recommendation for severe croup, doses as low as 0.15 mg/kg have shown equivalent efficacy in moderate to severe cases 4
- For severe croup specifically, use the full 0.6 mg/kg dose to ensure maximal anti-inflammatory effect 1
Adjunctive Therapy with Nebulized Epinephrine
When to Use Epinephrine
- Nebulized epinephrine is indicated for moderate to severe croup with stridor at rest or significant respiratory distress 5
- Dose: 0.5 mL/kg of 1:1000 solution (maximum 5 mL) nebulized 1, 5
Critical Timing Considerations
- Epinephrine provides immediate relief but lasts only 1-2 hours, while dexamethasone takes 30 minutes to several hours to work but provides 24-72 hours of effect 1, 5
- Never discharge a patient within 2 hours of nebulized epinephrine administration due to risk of rebound symptoms 5
- Monitor for at least 2 hours after the last epinephrine dose before considering discharge 5
Assessment and Monitoring Timeline
Initial Response Evaluation
- Dexamethasone onset of action begins as early as 30 minutes, with clinical duration of 24-72 hours 1
- Expect symptomatic improvement within the first few hours of treatment 4
Hospitalization Criteria
- Consider admission if three or more doses of racemic epinephrine are required 5
- Other admission indicators include: oxygen saturation <92-94%, age <18 months, respiratory rate >70 breaths/min, or persistent severe respiratory distress 5
- Maintain oxygen saturation ≥94% with supplemental oxygen as needed 5
Important Clinical Pitfalls
What NOT to Do
- Never use nebulized corticosteroids from hand-held inhalers with spacers—they are ineffective for croup 1, 6
- Do not use nebulized epinephrine in outpatient settings where immediate return is not feasible, as rebound symptoms can occur 5
- Avoid empirical treatment for asthma unless other features consistent with asthma are present 5
- Humidified or cold air provides no demonstrable benefit 5, 7
Steroid Safety
- A single dose of dexamethasone does not require tapering and does not cause significant adrenal suppression 1
- Corticosteroid-induced complications in croup are rare 2
- The only potential significant adverse effect is increased risk of severe varicella infection, though this is minimal with single-dose therapy 8
Alternative Corticosteroid Options
- Nebulized budesonide (2 mg) is equally effective as oral dexamethasone but oral administration is simpler and more practical in most settings 1, 8
- Prednisolone 1-2 mg/kg (maximum 40 mg) can be used if dexamethasone is unavailable 5
Follow-Up Instructions
- If discharged home, the child should be reviewed by a physician if deteriorating or not improving after 48 hours 5
- Provide families with information on managing fever, preventing dehydration, and identifying signs of deterioration 5
- Ensure reliable family able to monitor and return if worsening before discharge 5