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Assessment of stridor in children

Diana R Quintero, MD
Khoulood Fakhoury, MD
Section Editor
Gregory Redding, MD
Deputy Editor
Alison G Hoppin, MD


Stridor describes a high-pitched, monophonic sound made when breathing that is best heard over the anterior neck. These characteristics distinguish stridor from typical wheezing due to diffuse airflow limitation (asthma or bronchiolitis), which tends to consist of multiple sounds that start and stop at different times. The term is derived from the Latin verb stridere, meaning to make a harsh noise or shrill sound, as to creak.

Stridor is caused by the oscillation of a narrowed airway, and its presence suggests significant obstruction of the large airways. The acoustics of stridor may be explained as a result of Bernoulli's Principle, which states that as the speed of a moving fluid increases, the pressure within the fluid decreases. In an application in which airflow is forced through a narrowed tube, a local area of low pressure creates a vacuum effect distal to the narrowing. The focal area of low pressure distal to a narrowed airway causes the airway walls to collapse and vibrate, generating the squeak characteristic of stridor [1].

A commonly encountered presenting symptom in the pediatric population, stridor is an important physical finding that requires prompt evaluation and occasionally requires emergency intervention. The pathophysiology, differential diagnosis, and clinical management of stridor will be reviewed here. Related material is found in the following topics:

(See "Emergency evaluation of acute upper airway obstruction in children".)

(See "Evaluation of wheezing in infants and children".)

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Literature review current through: Nov 2017. | This topic last updated: Oct 06, 2017.
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