What is croup?

Croup: Definition and Management

Croup is a common upper airway infection characterized by a barking cough, stridor, hoarseness, and respiratory distress caused by inflammation of the larynx, trachea, and bronchi, primarily affecting children between 6 months and 3 years of age. 1, 2

Clinical Presentation

• Classic symptoms:

  • Barking or "seal-like" cough
  • Inspiratory stridor
  • Hoarse voice
  • Respiratory distress with varying severity
  • Often preceded by upper respiratory symptoms (coryza, low-grade fever)

• Typical course:

  • Usually begins with cold-like symptoms
  • Cough and respiratory symptoms typically worsen at night
  • Most cases resolve within 2 days 1
  • Symptoms can range from mild to severe

Etiology

• Viral causes predominate:
  • Parainfluenza virus (types 1-3) is the most common cause 3
  • Other viruses include:
    • Human metapneumovirus
    • Respiratory syncytial virus
    • Adenovirus
    • Influenza virus (more common in older children) 4
    • SARS-CoV-2 (including Omicron variants which can cause severe presentations) 5

Epidemiology

• Affects approximately 3% of children 6 months to 3 years of age 2
• Accounts for up to 15% of emergency department visits for respiratory disease in children 1
• Only 1-8% of croup cases require hospitalization 1
• Less than 3% of hospitalized patients require intubation 1

Diagnosis

• Primarily a clinical diagnosis based on characteristic symptoms
• Laboratory studies are rarely needed 2
• Differential diagnoses to consider:
  • Bacterial tracheitis
  • Epiglottitis
  • Foreign body aspiration
  • Peritonsillar abscess
  • Retropharyngeal abscess
  • Angioedema 1

Management

Pharmacological Treatment

1. Corticosteroids:

   • Dexamethasone is the cornerstone of treatment for ALL croup cases, including mild disease 1, 6
   • Single dose of 0.15-0.60 mg/kg orally, intramuscularly, or intravenously 1, 2
   • Benefits include reduced symptom severity, fewer return visits, and shorter hospital stays

2. Nebulized epinephrine:

   • Reserved for moderate to severe croup 1, 6, 2
   • Dosage: 4 mL of 1:1000 (undiluted) via nebulizer for severe cases 7
   • Provides temporary relief of symptoms (2-3 hours)
   • Patients should be observed for at least 2-3 hours after administration to monitor for symptom rebound

Observation Guidelines

• Mild croup: Home management with dexamethasone and caregiver education
• Moderate croup: Consider extended observation (up to 2 hours) after treatment 3
• Severe croup: Hospital admission, especially after 3 or more doses of racemic epinephrine 3

Hospitalization Criteria

• Persistent stridor at rest despite treatment
• Significant respiratory distress
• Need for 3 or more doses of racemic epinephrine 3
• Inability to maintain oral hydration
• Inadequate caregiver resources or significant parental anxiety

Special Considerations

• Influenza-associated croup in older children:

  • Often more severe than parainfluenza-caused croup
  • Higher risk of bacterial superinfection and tracheitis 4
  • May require more aggressive management

• COVID-19 associated croup:

  • Omicron BA.2 variant has been associated with severe, potentially life-threatening croup
  • May not respond as well to conventional treatment 5
  • Lower threshold for close monitoring and hospitalization may be warranted

Prognosis

Most cases of croup are mild and self-limiting, with symptoms typically resolving within 2 days. With appropriate treatment, even moderate to severe cases generally have excellent outcomes.

Key Pitfalls to Avoid

1. Failing to give dexamethasone for mild croup - All children with croup should receive dexamethasone regardless of severity
2. Inadequate observation after epinephrine - Monitor for at least 2-3 hours for symptom rebound
3. Missing alternative diagnoses - Consider bacterial tracheitis or epiglottitis in severe or atypical presentations
4. Unnecessary imaging - Reserve radiography for cases where alternative diagnoses are suspected
5. Prolonged hospitalization - Most children with croup who receive appropriate treatment can be safely discharged after observation