It is important to recognize the differences between the pediatric and adult upper airways to fully understand why even a relatively minor obstruction can cause significant airway compromise in children. The pediatric airway is shorter and narrower, and the larynx is placed more anterior than in adults. Young children, and infants especially, have a large tongue in relation to the small oropharynx. They also have a larger epiglottis. Signs of partial inspiratory obstruction include stridor (a high-pitched sound heard on inhalation), hoarseness, and increased work of breathing (suprasternal and intercostal retractions). Stridor can be inspiratory or expiratory, depending on whether the obstruction is supraglottic or subglottic, respectively. If the obstruction is severe or near-complete, worsening agitation, cyanosis, and respiratory failure likely will occur. Although acute stridor usually is infectious in etiology, other disorders may be present, especially when symptoms are severe or persistent. This chapter discusses inspiratory airway obstruction of infectious and noninfectious origin.
NONINFECTIOUS CAUSES OF UPPER AIRWAY OBSTRUCTION
Laryngomalacia is the most common cause of noninfectious, persistent stridor in infants. It is characterized by an omega-shaped epiglottis that is tightly curled, with varying degrees of prolapse of the arytenoid mucosa and cartilage during inspiration. The supraglottic structures prolapse into the airway, leading to obstruction during inspiration. The inspiratory stridor can begin in the first 2 weeks after birth, and it commonly worsens with crying and feeding. Choking, cough, and regurgitation frequently occur during feeding. Diagnosis can be based on the history and physical examination; however, a flexible fiberoptic laryngoscopy performed at bedside or in the clinic confirms the diagnosis. The condition usually resolves by 12 to 18 months. In more severe cases, surgery (supraglottoplasty) may be necessary. Gastroesophageal reflux disease (GERD) has been linked to laryngomalacia, and the possibility of concurrent reflux should be considered and treated. GERD may worsen the symptoms of laryngomalacia by contributing to further inflammation and edema of the larynx.
Laryngeal cysts and webs are much less common conditions that can cause airway obstruction. Depending on the degree of obstruction, they can present soon after birth. Laryngeal cysts can present with dysphagia, hoarseness, and stridor. Diagnosis is made via airway endoscopy, and treatment requires resection. Laryngeal webs are rare congenital anomalies that can present in the newborn period, causing respiratory distress and stridor. Severity of symptoms depends on the thickness of the web and whether they are incomplete or complete. The most severe condition along the spectrum of laryngeal webs is laryngeal atresia, which presents at birth and requires immediate intervention with tracheotomy. Treatment includes surgical approaches such as laryngotracheal reconstruction. Infants with congenital laryngeal anomalies should have a genetic and cardiovascular evaluation to screen for other syndromes that may occur in conjunction.
Thyroglossal duct cysts (originating from the thyroglossal duct) can present early in infancy in addition to later in childhood and even ...