Viral etiology; barky cough

Most common at age 6 months-3 years; peak 1 year

AP radiograph: Symmetric subglottic tracheal narrowing produces lack of normal “shouldering” of subglottic trachea; results in “steeple” sign

Lateral radiograph: Hypopharyngeal distension and ill-defined narrow subglottic airway

Radiographs obtained to exclude other causes of stridor: Exudative tracheitis, epiglottitis, aspirated foreign body (FB), or subglottic hemangioma

Coins are most common radiopaque FB in esophagus

If not passed, causes edema anterior to esophagus and around trachea; results in inspiratory stridor

Most common site: Upper thoracic esophagus followed by level of arch/carina and distal esophagus

Button batteries show 2-layered margin; require emergent removal to prevent caustic esophageal burn injury

If radiodense, see FB posterior to trachea

± thickening of soft tissue between esophagus and trachea

± anterior displacement of trachea

± tracheal narrowing at level of FB

Purulent infection → intratracheal exudates may slough & occlude airway

Usually older than patients with croup

Symmetric (or asymmetric) subglottic narrowing

± linear, soft tissue densities (membranes) within trachea ± tracheal wall irregularities (plaques)

Inspiratory stridor, airway obstruction, hoarseness or abnormal cry; usually younger than 6 months

Associated with cutaneous hemangiomas in up to 50% of patients

7% of patients with PHACE syndrome have subglottic hemangioma

Asymmetric subglottic tracheal narrowing on radiographs

Enhancing soft tissue mass on CT or MR

Infantile trachea lacks rigidity

Symptoms: Stridor, apnea, dyspnea; usually resolve as child grows

Increased incidence with esophageal atresia; dilated esophageal pouch deviates trachea forward, innominate artery compresses anterior trachea

Anterior tracheal narrowing at crossing innominate artery; below thoracic inlet

Secondary to complete cartilaginous rings ± associated anomalies such as vascular ring

Small caliber round (rather than horse shoe-shaped) trachea on cross sectional imaging

Inverted T-shaped carina on conventional radiograph or coronal reformatted CT images

Focal or diffuse stenosis possible

Smooth focal narrowing (ET tube) or irregular longer narrowing (tracheostomy secondary to granulation tissue ± structural damage to tracheal rings)

Life threatening infectious inflammation and swelling of epiglottis and supraglottic structures

Abrupt onset of stridor, dysphagia, high fever, sore throat, dysphonia, hoarseness, and drooling

Symptoms of airway obstruction markedly increase when recumbent; do lateral radiograph in upright position

Incidence markedly decreased since H. influenzae vaccination became universal

Enlargement of epiglottis & thickening of aryepiglottic folds on lateral X-ray

Rarely associated with tightly constricting left ligamentum arteriosum; presents with congenital stridor

Posterior esophageal indentation by aberrant SCA may cause dysphagia or feeding difficulties in infants

Posterior esophageal indentation by aberrant SCA on esophagram

Aberrant SCA coursing posterior to esophagus on CT or MR

Bronchial FB much more common than tracheal FB

Most airway FB not radiopaque; majority peanuts and carrots

Incident usually not witnessed

If radiodense, identify FB in airway