In a 22‑month‑old child weighing 10.94 kg with acute viral croup, what is the recommended dexamethasone dose and route, and when should nebulized epinephrine or nebulized budesonide be added?

Management of Acute Viral Croup in a 22-Month-Old Child

For this 22-month-old child with acute viral croup, administer oral dexamethasone 0.6 mg/kg (approximately 6.6 mg for 10.94 kg) as a single dose, add nebulized epinephrine immediately if the child has moderate-to-severe respiratory distress (stridor at rest, retractions, or croup score >3), and reserve nebulized budesonide only when oral/IM dexamethasone is unavailable or contraindicated. 1, 2

Dexamethasone Dosing and Route

The standard dose is 0.6 mg/kg (maximum 10-12 mg) given orally as the first-line route. 1 For this 10.94 kg child, this equals approximately 6.6 mg. The oral route is preferred because it is easy to administer, widely available, and low cost. 1

• Oral administration works rapidly: Clinical benefit begins at 30 minutes and is statistically significant by that timepoint, much earlier than previously thought. 3 This rapid onset makes oral dosing practical even in moderately severe cases.

• Lower doses (0.15 mg/kg) are equally effective for moderate-to-severe croup based on randomized trials showing no difference in croup score reduction, hospitalization duration, or need for additional interventions between 0.15 mg/kg and 0.6 mg/kg. 2, 4 However, the 0.6 mg/kg dose remains the standard recommendation in current guidelines and has the strongest evidence base across all severities. 1

• Intramuscular dexamethasone (same 0.6 mg/kg dose) is reserved for children who are vomiting or in severe respiratory distress unable to tolerate oral medication. 1

When to Add Nebulized Epinephrine

Nebulized racemic epinephrine should be added immediately for children with moderate-to-severe croup, defined by: 5

• Stridor at rest (not just with agitation)
• Subcostal or intercostal retractions
• Croup score >3 after initial assessment
• Significant respiratory distress preventing feeding or talking

Dosing: Nebulized racemic epinephrine 0.5 mL of 2.25% solution diluted in 3 mL normal saline, delivered via oxygen-driven nebulizer. 5 This can be repeated every 15-30 minutes if inadequate response. 6

• Critical observation period: Children receiving nebulized epinephrine must be observed for at least 4 hours after treatment before discharge, as the effect is temporary (peaks at 30 minutes, wanes by 2 hours) and rebound worsening can occur. 5 Discharge is safe only if the child appears clinically well to an experienced physician after this observation period and close follow-up is established. 5

• Epinephrine provides rapid but temporary relief while dexamethasone's anti-inflammatory effects take hold over 30 minutes to several hours. 3

Role of Nebulized Budesonide

Nebulized budesonide is NOT first-line therapy and should only be used when oral or intramuscular dexamethasone is unavailable or contraindicated. 1

• Budesonide has been shown effective in some geographic locations, but oral dexamethasone is preferred due to ease of administration, lower cost, and equivalent efficacy. 1

• If budesonide must be used, the dose is 2 mg nebulized as a single treatment. However, this is rarely necessary in modern practice given dexamethasone's availability and superiority in practical terms.

Hospital Admission Criteria

Assess for features requiring admission: 6

• Too breathless to feed
• Respiratory rate >50/min
• Heart rate >140/min (for this age, normal is 100-140/min)
• Use of accessory muscles
• Poor response to initial nebulized epinephrine (persistent stridor at rest or retractions after 30-60 minutes)
• Hypoxia or cyanosis
• Lethargy or altered consciousness

Common Pitfalls to Avoid

• Do not withhold dexamethasone in mild croup: Even children with mild disease (croup score 1-3) benefit from 0.15-0.6 mg/kg dexamethasone, with evidence of faster symptom resolution and reduced return visits. 3, 4 Corticosteroid-induced complications in croup are rare. 1

• Do not discharge immediately after epinephrine: The mandatory 4-hour observation period is critical to detect rebound worsening. 5

• Do not use nebulized budesonide as first-line when dexamethasone is available: This adds unnecessary cost and complexity without benefit. 1

• Do not underdose dexamethasone out of fear of side effects: The 0.6 mg/kg dose has an excellent safety profile, and lower doses (0.15 mg/kg), while effective, may not provide the same margin of benefit across all severities. 1, 2

Follow-Up Instructions

Provide clear return precautions: 6

• Worsening stridor or breathing difficulty
• Inability to feed or drink
• Lethargy or decreased responsiveness
• Cyanosis or pallor

Arrange primary care follow-up within 48 hours to ensure complete resolution and assess for recurrence. 6