International Board of Certified Lactation Consultant (IBCLC) Practice Exam

What is the most common cause of stridor in infants?

1. Asthma

2. Croup

3. Laryngomalacia

4. Foreign body aspiration

The correct answer is: Laryngomalacia

The most common cause of stridor in infants is laryngomalacia. Laryngomalacia is characterized by the softening of the tissues of the larynx (voice box), leading to a collapse of the airway during inhalation. This condition is often noted in infants shortly after birth and typically presents as a high-pitched sound when the infant breathes, particularly during periods of activity or agitation. Laryngomalacia is generally considered benign and often resolves on its own as the infant grows and the laryngeal structures become more developed and firm. This understanding is crucial for healthcare providers to differentiate it from other possible causes of stridor, which may require more immediate intervention or management. Asthma is less common in infants, as it typically develops later in childhood. Croup, while a notable cause of stridor, primarily occurs in children aged 6 months to 3 years and is associated with a viral infection that leads to inflammation of the upper airway. Foreign body aspiration can certainly cause stridor or wheezing, but it is typically associated with sudden onset following a choking event, rather than being a common cause in the general infant population. Consequently, laryngomalacia is recognized as the most prevalent cause of stridor in infants