Why are steroids, such as dexamethasone, given to pediatric patients with croup but not typically to those with bronchitis?

Why Steroids Are Given for Croup but Not Bronchitis

Steroids are given for croup because they directly target the subglottic airway inflammation that causes life-threatening upper airway obstruction, while bronchitis is a self-limited lower airway infection where steroids provide no proven benefit and may cause harm.

The Fundamental Pathophysiologic Difference

Croup: Upper Airway Emergency

• Croup involves inflammation of the larynx, trachea, and subglottic region, creating a critical narrowing of the upper airway that can progress to complete obstruction 1, 2
• The subglottic area is the narrowest part of a child's airway, and even small amounts of edema dramatically increase airway resistance and work of breathing 2
• Dexamethasone reduces this subglottic edema within 30 minutes to 2 hours, providing rapid relief of stridor and respiratory distress 1, 3, 4, 5
• Without treatment, croup can progress to respiratory failure requiring intubation 2

Bronchitis: Self-Limited Lower Airway Infection

• Bronchitis involves inflammation of the bronchi (lower airways) and is almost always viral and self-limiting, resolving in 7-10 days without treatment 6
• There is no evidence that steroids improve outcomes in acute bronchitis in children or adults 6, 7
• The inflammation in bronchitis does not cause the same critical airway narrowing seen in croup 7

Evidence-Based Outcomes That Matter

Proven Benefits in Croup

• A single dose of dexamethasone 0.6 mg/kg (maximum 16 mg) significantly reduces:
  • Duration of hospitalization (12 hours vs 20 hours with placebo) 4
  • Need for nebulized epinephrine (0% vs 20% with placebo) 4
  • Croup symptom scores within 1-2 hours 4, 5
  • Unscheduled return visits to medical care (7% vs 29% without optimal steroid) 8
• The effect lasts 24-72 hours, covering the typical disease course 1, 3

Lack of Benefit in Bronchitis

• No randomized controlled trials demonstrate benefit of steroids for nonspecific cough or acute bronchitis in children 7
• Oral steroids for nonspecific cough may actually increase hospitalizations according to an RCT of 200 children aged 1-5 years 7
• Acute laryngitis and bronchitis are self-limited, with improvement in 7-10 days with placebo treatment 6

Clinical Recognition and Treatment Algorithm

When to Give Steroids (Croup)

• Classic presentation: Sudden onset of barky "seal-like" cough, hoarse voice, inspiratory stridor, and respiratory distress 1, 2
• All children presenting to the ED with croup symptoms should receive steroids 2
• Dose: Dexamethasone 0.6 mg/kg orally (maximum 16 mg) as a single dose 1, 3, 2
• Route: Oral is preferred when tolerated; IM and IV are equally effective 1, 3
• For severe croup: Add nebulized epinephrine 0.5 mL/kg of 1:1000 solution (maximum 5 mL) while waiting for dexamethasone to take effect 1, 3

When NOT to Give Steroids (Bronchitis)

• Nonspecific cough without wheeze or stridor should NOT be treated with oral steroids 7
• Acute bronchitis in children should NOT receive routine steroid therapy 6, 7
• Exception: Only consider a short 2-4 week trial of inhaled corticosteroids (400 mcg/day budesonide equivalent) if clear asthma risk factors are present (personal atopy, family history of asthma, documented wheeze, or bronchodilator response on spirometry), with mandatory reassessment 7

Common Pitfalls to Avoid

In Croup Management

• Do not use prednisolone instead of dexamethasone - prednisolone results in 29% re-presentation rate vs 7% with dexamethasone 8
• Do not use lower doses - while 0.15 mg/kg may be effective, 0.6 mg/kg is the standard recommended dose with the best evidence 1, 9
• Do not use nebulized corticosteroids from hand-held inhalers with spacers - they are ineffective for croup 3

In Bronchitis Management

• Do not prescribe oral steroids for simple cough without clear evidence of asthma exacerbation 7
• Do not assume cough equals asthma - most children with nonspecific cough do not have asthma 7
• Do not routinely prescribe antibiotics - acute laryngitis and bronchitis are viral and self-limited 6

The Risk-Benefit Calculation

Why the Single Dose in Croup is Safe

• A single dose of dexamethasone does not require tapering and does not cause significant adrenal suppression 3
• The benefit (preventing airway obstruction and intubation) far outweighs minimal risks from a single dose 1, 2

Why Steroids Are Harmful in Bronchitis

• Systemic steroids have significant side effects including hyperglycemia, hypertension, gastrointestinal bleeding, growth suppression, and increased infection risk 6
• Long-term use can cause delayed growth, osteoporosis, adrenal suppression, cataracts, and adverse neurologic outcomes 6
• Without proven benefit, any risk is unacceptable 6, 7