Although radiographic evaluation of a child with stridor may not be helpful, lateral views of the neck and nasopharynx may provide information about adenoidal hypertrophyand airway swelling. On anteroposterior (AP) views of theneck taken with the head in extension, the subglottic spaceshould be symmetrical and the lateral walls of the airwayshould fall away steeply. Asymmetry suggests subglottic stenosis or a mass lesion, whereas tapering suggests subglotticedema. However, these findings may be subtle. Computedtomography (CT) scans of the upper airway can help delineate the site of the obstruction but may require sedationin younger children. Flexible nasopharyngoscopy/laryngoscopy, which can be done without sedation, is extremelyuseful in assessing airway patency, the presence of adenoidtissue, vocal cord and other airway lesions, and laryngomalacia. Bronchoscopy can be useful in assessing the subglottic space and intrathoracic large airways, but this procedurerequires sedation.
Appearance Normal to anxious Normal Anxious Agitated; toxic Anxious; toxic
Prevention None None None H. influenzae type None b conjugated vaccine
Prodrome/onset Insidious or sudden Sudden Sudden Biphasic Chronic with sudden worsening
Appearance Drooling Variable, usually normal Normal Drooling, trismus Normal CLINICAL/ HISTORICAL FEATURE RETROPHARYNGEAL ABSCESS FOREIGN BODY ANGIOEDEMA PERITONSILLAR ABSCESS LARYNGEAL PAPILLOMATOSIS
Fever Body temperature usually >38.5°C None None Body temperature None usually >38.5°C
Modified from Arnold JE: Airway obstruction in children. In Kliegman RM, Nieder ML, Super DM, editors: Practical Strategies in Pediatric Diagnosis and Therapy, Philadelphia, 1996, WB Saunders, p 126. FFP, Fresh frozen plasma; HPV, human papillomavirus; RSV, respiratory syncytial virus; URI, upper respiratory tract infection (with coryza, sneezing); WBC, white blood cell.
Table 135-3 Differentiating Supraglottic from Subglottic Causes of Airway Obstruction FEATURE SUPRAGLOTTIC OBSTRUCTION SUBGLOTTIC OBSTRUCTION Common clinical syndromes Epiglottitis, peritonsillar and retropharyngeal abscess Croup, angioedema, foreign body, tracheitis
Toxic Yes No, unless tracheitis is present
Facial edema No No, unless angioedema is present
Adapted from Davis H, Gartner JC, Galvis AG, et al: Acute upper airway obstruction: croup and epiglottitis, Pediatr Clin North Am 28:859–880, 1981.
The most common cause of chronic UAO in children is hypertrophy of the adenoids and tonsils. Adenoidal and tonsillar hyperplasia may be aggravated by recurrent infection, allergy, and inhaled irritants.
The signs of adenoidal and tonsillar hypertrophy are mouth breathing, snoring, and, in some patients, obstructive sleep apnea (see Chapter 134). The eustachian tubes enter the nasopharynx at the choanae and can be obstructed by enlarged adenoids, predisposing to recurrent or persistent otitis media.
Adenoidal hypertrophy is assessed by a lateral radiograph of the nasopharynx or by flexible nasopharyngoscopy.