- AKA acute laryngotracheobronchitis
- Usually caused by a parainfluenza virus or respiratory syncytial virus.
- Most common cause of upper respiratory distress in infants and young children, with the highest incidence between the ages of 6 months and 3 years.
- Child classically presents with inspiratory stridor and a barking cough.
- Croup is usually self-limited, with a good prognosis.
- Treatment is directed toward improving air exchange. Conservative measures, nebulized racemic epinephrine, and corticosteroids are commonly used.
 Imaging Findings
 Plain film
- Steeple sign is seen on anteroposterior radiographs of the soft tissues of the neck.
- Normal lateral convexities of the subglottic trachea are lost, and narrowing of the subglottic lumen produces an inverted V configuration in this area.
- Point of the inverted V is at the level of the inferior margin of the true vocal cords.
- Narrowing of the subglottic lumen alters the radiographic appearance of the tracheal air column, which resembles a steeply pitched roof or a church steeple.
- The lateral radiograph of the upper airway will show a normal epiglottis and narrowing of the subglottic region.
 See Also
 External Links
- Mozhdeh Salour. The Steeple Sign. Radiology 2000 216: 428-429.