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. Other etiologies including Ludwig's angina and oropharyngeal trauma are covered in Chapter 153.
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. Children ages 6 months to 3 years are most commonly affected, with a peak at an age of 12 to 24 months.
Croup occurs mainly in late fall and early winter, typically, beginning with a 1- to 5-day prodrome of cough and coryza, 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 perceived as more severe at night. Physical examination classically shows a biphasic stridor, although the inspiratory component usually is much greater.
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. Lateral neck and chest radiographs may demonstrate the normally squared shoulders of the subglottic tracheal air shadow as a pencil tip, hourglass, or “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 milligrams/kilogram (10 milligrams max) PO or IM (may use the IV formulation orally). Nebulized budesonide (2 milligrams) may be clinically useful in moderate to severe cases. Even patients with very mild croup symptoms benefit from steroids, therefore most ED patients diagnosed with croup should be treated with corticosteroids.
Nebulized racemic epinephrine, 0.05 mL/kg/dose up to 0.5 mL of a 2.25% solution, should be used to treat moderate to severe cases (significant stridor at rest). Alternatively L-epineprhine (1:1000), 0.5 mL/kg (to a maximum of 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 results in less than a 1% intubation rate. When necessary, consider a smaller endotracheal tube than estimated by age to avoid trauma to the inflamed mucosa.
Helium plus oxygen (Heliox), typically in a 70:30 mixture, may prevent the need for intubation in the most ...