What is the recommended dose of dexamethasone (corticosteroid) for a 3-year-old child weighing 28 pounds with a croupy cough?

Dexamethasone Dosing for Croup in a 3-Year-Old

Give dexamethasone 0.6 mg/kg orally as a single dose (approximately 7.6 mg for this 28-pound/12.7 kg child), which is the standard evidence-based treatment for croup in children presenting with croupy cough. 1, 2

Dosing Specifics

• Standard dose: 0.6 mg/kg orally as a single dose (maximum 10-12 mg) 3, 1, 2
• For this 28-pound child (12.7 kg): Give approximately 7.6 mg of dexamethasone orally 4, 3
• Route of administration: Oral is preferred due to ease of administration, availability, and low cost 3, 2
• Intramuscular alternative: Use IM route only if the child is vomiting or in severe respiratory distress and unable to tolerate oral medication 4, 3

Lower Dose Consideration

• Alternative dosing: 0.15 mg/kg may be equally effective for moderate-to-severe croup (approximately 1.9 mg for this child) 5, 1
• Evidence shows 0.15 mg/kg and 0.6 mg/kg are equally effective in reducing croup scores, with no difference in return visits, hospital length of stay, or need for additional treatments 5, 1
• However, 0.60 mg/kg probably reduces croup severity better at 24 hours compared to 0.15 mg/kg 1
• Clinical decision: While lower doses may work, the 0.6 mg/kg dose remains the standard recommendation given its robust evidence base and established efficacy 3, 2

Expected Clinical Response

• Onset of action: Approximately 6 hours after administration 4
• Symptom improvement: Significant reduction in croup scores occurs by 2 hours, with continued improvement at 6,12, and 24 hours 1
• Duration: Single dose is typically sufficient 3, 1

Concurrent Management

• If severe respiratory distress: Consider racemic epinephrine by nebulizer for rapid symptom relief while waiting for dexamethasone to take effect 4
• Monitoring: If epinephrine is used, observe for at least 2 hours for rebound airway obstruction 4
• Humidified air: Maintain at least 50% relative humidity in the child's environment 4
• Oxygen: Provide supplemental oxygen if hypoxemia is present 4

Critical Pitfalls to Avoid

• Do not use lower doses than 0.15 mg/kg: Doses below this threshold have proven ineffective in treating croup 4
• Do not withhold steroids: Corticosteroids are the mainstay of treatment for moderate-to-severe croup and reduce hospitalizations, length of illness, and need for subsequent treatments 3, 1
• Do not use dexamethasone for chronic or non-specific cough: This medication is specifically for acute croup, not for other types of cough in children 6, 7
• Avoid over-the-counter cough suppressants: Codeine and other cough medications are associated with significant morbidity and mortality without proven benefit 6

Safety Profile

• Corticosteroid-induced complications in croup are rare 3
• Single-dose dexamethasone for croup is well tolerated, effective, and inexpensive 3, 1
• No significant adverse reactions were observed in studies comparing different dexamethasone doses 5