What is the recommended dose of dexamethasone (corticosteroid) for the management of croup?

Dexamethasone for Croup: Recommended Dosing

For children with croup, administer a single dose of oral dexamethasone 0.6 mg/kg (maximum 10-12 mg), which is the standard of care for moderate-to-severe disease and has been shown to reduce hospitalizations, shorten illness duration, and decrease need for subsequent treatments. 1, 2

Dose Selection by Severity

Moderate-to-Severe Croup

• Use 0.6 mg/kg oral dexamethasone (maximum 10-12 mg) as the standard dose 1, 2
• This dose has become the universal standard based on decades of evidence showing reduced hospitalizations and need for additional interventions 2, 3
• Intramuscular administration at the same dose (0.6 mg/kg) is equally effective and reserved for patients who are vomiting or in severe respiratory distress unable to tolerate oral medication 2, 3

Mild Croup

• Consider lower doses of 0.15-0.3 mg/kg for mild, potentially self-limiting disease 2, 4
• Evidence supports that 0.15 mg/kg is as effective as higher doses in relieving symptoms and results in similar hospitalization duration 4, 5
• A randomized trial of 120 children demonstrated no difference in croup score reduction, hospitalization duration, or need for nebulized epinephrine between 0.15 mg/kg, 0.3 mg/kg, and 0.6 mg/kg doses 4

Route of Administration

• Oral administration is strongly preferred due to ease of use, availability, and low cost 1, 2
• Oral and intravenous dexamethasone have equivalent bioavailability (1:1 conversion) 1
• When IV administration is necessary, infuse slowly over several minutes to avoid perineal burning 1
• Intramuscular route should be used only when oral administration is not feasible 2, 3

Clinical Outcomes and Evidence Quality

The evidence supporting dexamethasone use in croup is robust:

• At 12 hours post-administration, median croup scores decline significantly (from 4.5 to 1.0 in one randomized controlled trial) 6
• By 24 hours, 85% of patients receiving dexamethasone show improvement (decline of ≥2 points in croup score) compared to 33% with placebo 6
• Only 19% of dexamethasone-treated patients require ≥2 racemic epinephrine treatments versus 62% of placebo patients 6
• A study of 277 outpatients found no significant difference between oral and intramuscular routes, with 51% achieving complete symptom resolution and only 8% requiring additional interventions 3

Adjunctive Therapy

• For moderate-to-severe croup, consider nebulized epinephrine (0.5 ml/kg of 1:1000 solution) for immediate symptom relief while dexamethasone takes effect 1
• Nebulized budesonide (500 µg) may reduce symptoms in the first 2 hours but lacks long-term outcome data and is less commonly used than oral dexamethasone 1

Important Clinical Considerations

• Corticosteroid-induced complications in croup are rare 2
• Antifungal prophylaxis should be considered only in patients receiving prolonged steroid therapy, which is not typical for croup management 1
• A single dose is typically sufficient; no tapering is required for this short-course treatment 2, 3
• Follow-up is important as approximately 29% of patients may return for further evaluation, though only 8% require additional interventions 3

Common Pitfalls to Avoid

• Do not withhold corticosteroids from patients with mild croup who seek medical care—evidence supports treatment across all severity levels, though lower doses may be appropriate 2, 4
• Do not use intramuscular route routinely—reserve it only for patients unable to tolerate oral medication 2
• Do not assume higher doses are more effective—studies demonstrate equivalent efficacy between 0.15 mg/kg and 0.6 mg/kg for most patients 4, 5