What condition is characterized by stridor, a high-pitched wheeze?

The condition characterized by stridor, which is a high-pitched wheezing sound, is typically associated with upper airway obstruction. Stridor occurs when there is a disturbance of airflow in the upper airway, often due to obstruction or narrowing from various causes such as swelling, foreign bodies, or structural abnormalities. This sound is a prominent indication that the upper airway is compromised, requiring immediate assessment and intervention.

In contrast, the other options generally involve lower airway issues or different pathophysiological processes. Asthma exacerbation is associated with wheezing but is typically heard during expiration rather than presenting with the high-pitched sound characteristic of stridor. Pneumothorax involves the presence of air in the pleural space and can lead to decreased breath sounds rather than stridor. Chronic bronchitis is a lower respiratory condition marked by a productive cough and wheezing that is often more pronounced during expiration, differing significantly from the presentation of upper airway obstruction. Therefore, the distinctive feature of stridor aligns directly with upper airway obstruction as the correct identification of the condition.