The physical sign common to all causes of upper respiratory tract obstruction is stridor. Laryngomalacia, due to a developmentally weak larynx, accounts for 60% of stridor in the neonatal period, but is self-limited and rarely requires treatment. Common causes of stridor in children >6 months of age discussed here include viral croup, epiglottitis, bacterial tracheitis, airway foreign body, retropharyngeal abscess, and peritonsillar abscess.
VIRAL CROUP (LARYNGOTRACHEOBRONCHITIS)
Viral croup is responsible for most cases of stridor after the neonatal period. It is usually a benign, self-limited disease caused by edema and inflammation of the subglottic area. Croup is most prevalent in the fall and early winter, and children ages 6 months to 3 years are most commonly affected, with a peak at an age of 12 to 24 months.
Croup typically begins with a 1- to 3-day prodrome of cough, coryza, and low-grade fever, followed by a 3- to 4-day period of classic barking cough, though cough and stridor may be abrupt in onset. Symptoms peak on days 3 to 4 and are often more severe at night. Physical examination classically shows stridor, with a greater inspiratory component. Severe cases may have stridor at rest, tachypnea, nasal flaring, and retractions.
Diagnosis and Differential
The diagnosis of croup is clinical: a barking, seal-like cough and history or finding of stridor in the appropriate setting is diagnostic. The differential diagnosis includes epiglottitis, bacterial tracheitis, or foreign body aspiration. Radiographs are not necessary, unless other causes are being considered. Neck or chest radiographs may demonstrate subglottic narrowing or the “steeple sign,” though this sign is neither sensitive nor specific for croup.
Emergency Department Care and Disposition
Patients with significant stridor should be kept in a position of comfort with minimal disturbance; monitor pulse oximetry and provide oxygen as needed.
Administer dexamethasone 0.15 to 0.6 mg/kg (10 mg maximum) PO or IM (may use the IV formulation orally). Nebulized budesonide (2 mg) may also be clinically useful, if unable to tolerate oral treatment. Even patients with mild croup symptoms benefit from steroids; therefore, most ED patients diagnosed with croup should be treated with a single dose of corticosteroids.
Nebulized racemic epinephrine (2.25%), 0.05 mL/kg/dose up to 0.5 mL, should be used to treat moderate to severe cases (significant stridor at rest). Alternatively L-epinephrine (1:1000), 0.5 mL/kg/dose up to 5 mL, can be used. Children with stridor associated only with agitation do not need epinephrine.
Although intubation should be performed when clinically indicated, aggressive treatment with epinephrine usually prevents intubation. When necessary, consider a smaller endotracheal tube than estimated by age to avoid trauma to the inflamed mucosa.
Heliox (70% helium/30% oxygen mixture) has theoretical benefits for severe refractory croup given its decreased airway resistance, though studies have shown no definitive advantage and it is limited by the ...