• Malacia refers to “softness” of airway structures.
  • Laryngomalacia
    • Dynamic collapse of the supraglottic structures of the larynx resulting in airway obstruction
    • Most common congenital anomaly of the larynx
    • Most common noninfectious cause of stridor in children
  • Tracheomalacia
    • Dynamic collapse of the trachea resulting in airway obstruction during forceful respiratory maneuvers
    • Common cause of chronic wheezing in infants and children
    • Clinical manifestations depend on if lesion is part of the intrathoracic or extrathoracic portions of the trachea.
      • Intrathoracic tracheomalacia: Airway collapse occurs during exhalation because pleural pressure exceeds luminal pressure.
      • Extrathoracic tracheomalacia: Airway collapse occurs during inhalation because atmospheric pressure exceeds luminal pressure.


  • Laryngomalacia
    • Anatomic abnormalities:
      • Short aryepiglottic folds
      • Elongated, flaccid, omega-shaped epiglottis prolapses posteriorly.
      • Redundant arytenoid mucosa
    • Neurologic abnormalities:
      • Immaturity of neuromuscular control results in hypotonia of pharyngeal muscles.
  • Tracheomalacia
    • Weakness of the tracheal wall secondary to softening of the anterior cartilaginous rings and/or decreased tone of the posterior membranous wall
    • Classified as primary or secondary
      • Primary: congenital; most common congenital tracheal abnormality occurring in 1:2,100 children; results from immature development of the tracheal structures; may occur with other congenital anomalies such as tracheoesophageal fistula, laryngomalacia, and facial anomalies
      • Secondary: acquired in a normally developed trachea after some insult such as prolonged positive pressure ventilation, recurrent infection or aspiration, or external compression
    • With increasing age, the length, area, thickness, and amount of cartilage increases in the anterior rings as well as the size and contractility of the membranous wall.

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