Most children presenting with the classic “barky” cough and stridor have croup. Nonetheless, other potentially more serious entities may manifest as stridor and present similarly to croup. Emergency clinicians need to stay vigilant to identify and treat these children appropriately. (See Table 1.) Common causes of acute febrile stridor are bacterial tracheitis, epiglottitis, and retropharyngeal abscess. Acute afebrile stridor may be due to foreign body aspiration, spasmodic croup, thermal or caustic injury to the airway, or angioneurotic edema. Patients with accidental or intentional strangulation may also present with stridor. Emergency clinicians should inspect the neck for external signs of injury and consider the possibility of nonaccidental injury if other aspects of the history are suspicious. Chronic stridor is usually caused by laryngomalacia, vascular anomalies, or adenotonsillar hyperplasia.26-27
Bacterial tracheitis is an acute infectious illness that causes subglottic edema and accumulation of purulent secretions in the larynx.16 The primary bacterial infection is characterized by high fever, toxic appearance, and acute onset of stridor that does not respond well to usual therapy, especially nebulized epinephrine. The infection may also be superinfection sequelae of viral croup. Common pathogens include Group A streptococcus, Streptococcus pneumoniae, S aureus and H influenzae. Early differentiation of bacterial tracheitis from croup is important, as the management of the two are very different. Management of bacterial tracheitis includes intravenous (IV) antibiotics and usually mandates hospital admission. Some patients may require intubation and ventilatory support.
Epiglottitis remains a critical component to the differential diagnosis of the acute onset of fever and stridor; however, since the introduction of universal immunization against H influenzae type b, its incidence has dramatically decreased in the pediatric population. Nonetheless, its accompanying high mortality still makes it a diagnosis that cannot be delayed or missed. Culprit pathogens now include nontype b H influenzae strains, several streptococcus strains, S aureus, and Pasteurella multocida.28 Clinically, children with epiglottitis will have a toxic appearance and high fever and will present with drooling, a preference to sit in a tripod stance, refusal of food, dysphagia, and dysphonia. Croup can be distinguished by its viral prodrome of upper respiratory symptoms, barky cough, and chest retractions.29 These children are typically not ill-appearing. The most experienced and skilled clinicians should be consulted to secure the airway in these patients, as ventilatory support for respiratory failure is often required.
Retropharyngeal abscess is a rare cause of stridor. These patients usually present with fever; neck pain; marked decreased range of motion of the neck, sometimes accompanied by meningismus; and, rarely, with respiratory distress. Radiographic evaluation is often required to confirm diagnosis. Parenteral antibiotics, hospitalization, and concurrent ear, nose, and throat (ENT) consultation for potential surgical management are mainstays of therapy.
Afebrile and chronic causes of stridor will typically have a pertinent clinical history and physical signs to support their diagnoses. Patients with foreign body aspiration may present with a history of sudden choking or coughing. Often, however, this diagnosis is delayed because an acute event may not be witnessed. Structural anomalies commonly present during the newborn period as positional stridor that worsens progressively over the first few weeks of life; they may be more prominent during feeding or crying. Mild laryngomalacia may resolve spontaneously over time or may require surgical intervention by an ENT surgeon in certain cases. Gastroesophageal reflux may also cause stridor in infants and may present with feeding intolerance such as regurgitation or vomiting, poor weight gain, hoarse cry, and chronic cough.