Infectious Causes of Stridor in Infants and Young Children
Croup. Common causes of viral croup include parainfluenza virus (types 1 and 3), metapneumovirus, adenovirus, influenza virus, and respiratory syncytial virus (making up the pneumonic "PM AIR"). These viruses cause subglottic inflammatory edema, resulting in inspiratory or biphasic stridor, barking cough, and fever. Treatments for croup are aimed at decreasing the airway edema. Thus, aerosolized racemic epinephrine(Drug information on epinephrine) and oral corticosteroids are effective therapies.
Epiglottitis. Now less common in the era of routine vaccination against Haemophilus influenzae type b, this acute, rapidly progressive infection of the epiglottis and aryepiglottic folds often follows a viral prodrome. Patients have fever of acute onset, sore throat, and a toxic appearance. They will often hyperextend the neck and drool because of the inability to swallow secretions. Securing the airway is essential. Thus, emergent consultation with an otorhinolaryngologist or anesthesiologist for endotracheal intubation is paramount.
Retropharyngeal and peritonsillar abscesses. In children, infectious causes of stridor must also include retropharyngeal abscesses. An infection of the posterior pharynx is caused most commonly by Staphylococcus aureus or anaerobic bacteria. In addition to stridor, patients may have arching of the neck, drooling, and fever as well as a thickened retropharyngeal space apparent on a lateral neck radiograph. In contrast, a peritonsillar abscess tends to occur in children older than 10 years and is caused most commonly by group A streptococci and anaerobic bacteria. Both conditions may present with biphasic stridor.
Bacterial tracheitis. Bacterial superinfection of a previous viral laryngotracheobronchitis can occur, usually in children older than 2 years. This severe illness is the result of secondary infection, most commonly with S aureus and less commonly with Moraxella catarrhalis or H influenzae. Patients are toxic-appearing, with high fever, barking cough, stridor, and retractions, but usually maintain a normal position and exhibit no drooling or inability to manage secretions. Therapy includes ceftriaxone(Drug information on ceftriaxone), and in severe cases, patients may require endotracheal intubation.
Papillomatosis. These airway papillomas have a tendency toward spontaneous regression; however, they often necessitate laser therapy for years. Tracheostomy is avoided because this may predispose the patient to pulmonary parenchymal involvement. Human papillomavirus types 6 and 11, which can be acquired by passage through a birth canal affected with condyloma latum, can cause papillomatosis in an infant. Thus, obtaining a maternal history, especially in neonates and infants, is critical in the evaluation of stridor.
FOR MORE INFORMATION:
- Holinger LD. Congenital anomalies of the larynx, trachea, and bronchi. In: Kliegman RM, Behrman RE, Jenson HB, Stanton B, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia: Saunders; 2007:1767-1769.
- Kliegman RM, Arnold JE. Airway obstruction in children. In: Kliegman RM, Lye PS, Greenbaum LA, eds. Practical Strategies in Pediatric Diagnosis and Therapy. 2nd ed. New York: Elsevier Health Sciences; 2004:82-94.