Commonest cause of stridor in a newborn is?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2021

Child Health Nursing (Pediatrics)

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2021

Explanation

Laryngomalacia is the most common congenital anomaly of the larynx, responsible for 45-75% of stridor cases in infants.
It is caused by the immaturity and flaccidity of the supraglottic structures (epiglottis and arytenoids), which collapse inward during inspiration, creating turbulent airflow.
This collapse produces a characteristic high-pitched inspiratory stridor, which is the hallmark sign of the condition.
Symptoms typically manifest within the first few weeks of life and are often exacerbated by crying, feeding, or lying supine, and may improve in a prone position.
It is generally a benign condition that resolves spontaneously as the laryngeal cartilages mature and stiffen, usually by 18-24 months of age.

Option A: Foreign body aspiration is extremely rare in newborns because they lack the mobility and motor skills to place objects in their mouths. It is a more common cause of acute-onset stridor in toddlers.
Option C: Meconium aspiration syndrome presents at birth with generalized respiratory distress, including tachypnea, grunting, retractions, and cyanosis, rather than the isolated finding of stridor.
Option D: While a significant cause of congenital stridor, vocal cord paralysis is the second or third most common, not the most common. It is often associated with a weak or absent cry (aphonia) in addition to stridor.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of congenital stridor in newborns as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in assessing the severity of stridor and the infant's work of breathing, monitoring for retractions, cyanosis, or feeding difficulties that may signal a more severe case.
Parental education is a key nursing function. This includes teaching positioning techniques (e.g., prone position) and feeding strategies (e.g., smaller, frequent feeds) to manage symptoms.
It is vital to reassure parents that laryngomalacia is typically self-resolving while also equipping them to recognize warning signs (apnea, cyanosis, poor weight gain) that require immediate medical attention.

How to Approach the Question

First, identify the core of the question: it asks for the 'commonest cause' of a specific symptom ('stridor') in a specific population ('newborn').
This is a factual recall question that relies on knowledge of pediatric respiratory conditions.
Analyze the options in the context of a newborn. A 'foreign body' is highly unlikely due to the infant's immobility.
'Meconium aspiration' causes a broader, more severe respiratory distress syndrome at birth, not typically isolated stridor.
Differentiate between the remaining congenital laryngeal anomalies. Recall or deduce that 'Laryngomalacia' (the 'floppy larynx') is far more prevalent than 'Recurrent laryngeal nerve palsy'.
Select Laryngomalacia as the most statistically common etiology for stridor in this age group.

Concept Tested & Keywords

QZxwHBHm1Oj64Kn1qpr22S

E6 Ghai Essential Pediatrics(pp 26-904 of 913) pp. 392-394, 398-400

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 359-361