What is croup?

Croup: Definition and Management

Croup is a common respiratory condition characterized by inflammation and swelling of the upper airway, particularly the larynx and trachea, causing a distinctive barking cough, stridor, hoarse voice, and respiratory distress in young children, typically aged 6 months to 6 years. 1

Etiology and Epidemiology

• Most commonly caused by viruses, particularly parainfluenza viruses, though influenza and other viruses can also cause it 1
• Typically presents in late fall or early winter 2
• Most common cause of upper airway obstruction in children 6 months to 6 years of age 3
• Responsible for up to 15% of emergency department visits due to respiratory disease in children 3

Clinical Presentation

• Often preceded by upper respiratory infection symptoms 2
• Key clinical features include:
  • Barking or brassy cough (hallmark symptom) 4, 1
  • Inspiratory stridor
  • Hoarse voice
  • Respiratory distress of varying severity
  • Low-grade fever
• Symptoms typically worsen at night 1
• In most children, symptoms subside quickly with resolution of cough within two days 3

Severity Assessment

The Westley Croup Score is recommended to determine severity 1:

• Mild: Barking cough but no stridor at rest
• Moderate: Stridor at rest, some chest wall retractions
• Severe: Significant stridor at rest, significant retractions, decreased air entry

Parameter	0 points	1 point	2 points	3 points	4 points	5 points
Stridor	None	When agitated	At rest	-	-	-
Retractions	None	Mild	Moderate	Severe	-	-
Air entry	Normal	Decreased	Markedly decreased	-	-	-
Cyanosis	None	-	-	With agitation	At rest	-
Level of consciousness	Normal	-	-	-	-	Altered

Treatment

1. Corticosteroids: Single dose of dexamethasone (0.15-0.60 mg/kg orally) is recommended for ALL children with croup, even mild cases 1, 3

   • Onset of action is approximately 6 hours after administration 2
   • Highly efficacious in reducing symptoms 5

2. Nebulized epinephrine: For moderate to severe cases

   • 0.5 ml/kg of 1:1000 solution or 0.5 mL of 2.25% solution diluted in 2.5 mL of saline 1, 6
   • Provides rapid but temporary relief
   • Monitor for rebound airway obstruction for at least 2 hours after administration 2
   • Children requiring two epinephrine treatments should be hospitalized 6

3. Supportive care:

   • Maintain calm environment
   • Position child comfortably (often upright)
   • Ensure adequate hydration
   • Provide supplemental oxygen if saturation is <92% 1

Differential Diagnosis

Always consider other causes of stridor that may mimic croup 1:

• Epiglottitis
• Foreign body aspiration
• Retropharyngeal abscess
• Bacterial tracheitis
• Airway hemangioma
• Congenital anomalies of the larynx

Recurrent Croup

• Defined as two or more episodes per year 7
• Should be considered a symptom of an underlying structural or inflammatory airway abnormality
• Warrants investigation for underlying causes 7

Discharge and Admission Criteria

Discharge criteria 1:

• Significant improvement in symptoms
• No stridor at rest after treatment
• Ability to tolerate oral fluids
• No repeated doses of epinephrine required
• Oxygen saturation ≥92% on room air

Consider hospital admission if 1:

• Oxygen saturation <92% or cyanosis
• Persistent significant respiratory distress after treatment
• Stridor at rest that persists after treatment
• Need for more than one dose of nebulized epinephrine
• Inability to tolerate oral fluids
• Toxic appearance

Home Care

• Adequate hydration
• Humidification (though evidence for benefit is limited)
• Fever control
• Return to ED if increased work of breathing, lethargy, or inability to drink fluids 1, 6

Note: Antihistamines, decongestants, and antibiotics have no proven effect on uncomplicated viral croup 6