1 What are the four primary diagnostic considerations in a febrile child with acute stridor?

TABLE 26-1 illustrates clinical criteria helpful in distinguishing among the four.

2 What is the most common cause of stridor in the pediatric population?

Laryngotracheobronchitis (croup) accounts for >90% of all emergency department visits for stridor in the pediatric population. The key features of croup include barky cough, stridor, and hoarseness, usually preceded by symptoms of a mild upper respiratory tract infection. Croup is most common in older infants and toddlers, though it is not uncommon in school-aged children.

eMedicine: Stridor. Available at www.emedicine.com/ped/topic2159.htm.

3 Name three animal sounds to which the croup cough has been compared.

The bark of a seal or sea lion, the bark of a dog, and the honking of a goose.

4 What is meant by the term spasmodic croup?

Spasmodic croup, also known as laryngismus stridulus, is a variant of croup that lacks the typical viral prodrome (low-grade fever, runny nose). Symptoms start suddenly, often in the middle of the night, and resolve quickly. Symptoms may recur for several nights in a row. The etiology of spasmodic croup is unclear. Since the diagnosis can be made only upon resolution of the symptoms, the distinction between viral and spasmodic croup during initial presentation lacks clinical relevance.

5 What is the characteristic radiographic finding in a patient with croup? In epiglottitis?

The classic radiographic finding in croup is the “steeple sign,” a narrowing of the laryngotracheal air column just below the vocal cords on an anterior-posterior view (Fig. 26-1). Another finding includes “ballooning” (distention) of the hypopharynx during inspiration, seen on a lateral view. The steeple sign has been show to lack sensitivity and specificity. The primary reason for obtaining radiographs in children with suspected croup should be to evaluate the possibility of other causes of stridor in atypical cases. The classic finding in epiglottitis is the “thumb sign,” referring to the lateral view of the swollen epiglottis resembling a lateral view of one’s thumb (Fig. 26-2). The thumb sign is also subjective, and radiographs alone should not be used to diagnose epiglottitis. If clinical suspicion is high, imaging should be deferred in favor of direct visualization of the airway under controlled circumstances.

Figure 26-1 Radiographic view of the steeple sign.

Figure 26-2 Radiographic view of the thumb sign.

6 Which bacterial infection of the upper airway most closely clinically mimics croup: Epiglottitis, bacterial tracheitis, or retropharyngeal abscess?