What is the significance and management of the steeple sign in pediatric patients?

Steeple Sign: Radiographic Indicator of Subglottic Narrowing in Croup

The steeple sign on anteroposterior neck radiograph indicates subglottic narrowing from laryngotracheobronchitis (croup), and while it confirms the diagnosis, treatment decisions should be based on clinical severity rather than radiographic findings alone. 1

Clinical Significance

The steeple sign represents narrowing of the subglottic trachea visible on AP neck radiograph, creating a characteristic church steeple or pencil-point appearance of the normally shouldered tracheal air column. 1, 2

Key diagnostic points:

• The radiographic finding confirms subglottic edema but is not required for diagnosis—croup is primarily a clinical diagnosis based on barking cough, inspiratory stridor, and hoarseness. 3, 4
• Diagnostic imaging is usually unnecessary in typical presentations and should not delay treatment. 4
• The steeple sign helps differentiate croup from other causes of upper airway obstruction when the diagnosis is uncertain. 1

Critical Assessment for Severity

Before focusing on radiographic confirmation, immediately assess for signs of severe respiratory distress that indicate impending respiratory failure:

• Grunting: repetitive "eh" sounds during early expiration against a partially closed glottis 5
• Nasal flaring: consistent outward movement of the ala nasi during inspiration 5
• Head nodding: head moving upward and downward in synchrony with respiration from sternocleidomastoid and scalene muscle contraction 5, 6, 7
• Tracheal tugging: soft tissue over the trachea pulling inward during inspiration 5
• Intercostal retractions: tissue between ribs pulling inward during inspiration 5
• Severe tachypnea: ≥70 breaths/min in children 2-11 months or ≥60 breaths/min in children 12-59 months 5

Any of these signs indicate severe respiratory distress requiring immediate intervention, not just radiographic confirmation. 6

Management Algorithm Based on Clinical Severity

All Patients with Croup (Including Mild Disease)

Administer dexamethasone 0.15 to 0.60 mg/kg orally as a single dose—this is recommended for all patients with croup regardless of severity. 3, 4

• This reduces symptom severity, return visits to healthcare providers, emergency department visits, and hospital admissions. 4
• For patients unable to tolerate oral medication, use nebulized budesonide or intramuscular dexamethasone as alternatives. 4

Moderate to Severe Croup

Add nebulized epinephrine (racemic epinephrine) for patients with moderate to severe symptoms or stridor at rest. 3, 4, 8

• Simultaneous administration of corticosteroid and epinephrine reduces intubation rates in severe croup with impending respiratory failure. 4

Admission Criteria

Admit patients with: 8

• Stridor at rest
• Evidence of exhaustion
• Toxicity or significant respiratory distress
• Any signs of severe respiratory distress listed above 5, 6

Humidification

Humidified air administration is traditional supportive care, though evidence for benefit is lacking. 3, 8

Critical Differential Diagnoses to Exclude

Do not assume croup without considering these potentially life-threatening alternatives: 3

• Bacterial tracheitis: toxic appearance, high fever, purulent secretions
• Epiglottitis: drooling, tripod positioning, toxic appearance (though rare post-Hib vaccine)
• Foreign body aspiration: sudden onset without prodrome, unilateral findings
• Peritonsillar or retropharyngeal abscess: severe dysphagia, neck stiffness, asymmetric findings
• Angioedema: rapid onset, history of allergies or ACE inhibitor use

Common Pitfalls to Avoid

Do not delay treatment to obtain radiographs in clinically obvious croup—the steeple sign confirms diagnosis but does not change management. 4

Do not withhold corticosteroids in mild croup—early intervention reduces progression and healthcare utilization. 4

Do not discharge patients immediately after nebulized epinephrine—observe for at least 2-3 hours as the effect is temporary and rebound symptoms may occur. 8

Do not miss signs of severe respiratory distress by focusing only on stridor—head nodding, grunting, and severe retractions indicate impending respiratory failure requiring immediate escalation of care. 5, 6

Prognosis

Most croup episodes are mild, with only 1-8% requiring hospital admission and less than 3% of admitted patients requiring intubation. 3 Symptoms typically resolve within 2 days in most children. 3