- the most common cause of stridor in the newborn
- the laryngeal skeleton is not stiff enough to resist the negative pressure during inspiration causing narrowing and stridor
- can occur at birth but most commonly seen at 2 weeks of age, and is more pronounced with agitation
- for most, close observation is sufficient as the cartilage becomes more rigid with age
- usually outgrown by 12-18 months of age
- in severe cases, feeding may be affected and nighttime obstructive hypoxia may occur