Laryngomalacia is a condition affecting infants, where the part of the larynx above the vocal cords (the supraglottic larynx) is structured in a way that allows it to cause partial airway obstruction. This leads to a chronic stridor on inhalation, when the larynx flops across the airway as the infant breathes in. Stridor is a harsh whistling sound caused by air being forced through an obstruction of the upper airway.
Structural Changes
There are two aryepiglottic folds at the entrance of the larynx. They run between the epiglottis and the arytenoid cartilages. They are either side of the airway and their role is to constrict the opening of the airway to prevent food or fluids entering the larynx and trachea. In laryngomalacia the aryepiglottic folds are shortened, which pulls on the epiglottis and changes it shape to a characteristic “omega” shape.
The tissue surrounding the supraglottic larynx is softer and has less tone in laryngomalacia, meaning it can flop across the airway. This happens particularly during inspiration, as the air moving through the larynx to the lungs pulls the floppy tissue across the airway to partially occlude it. This partial obstruction of the airway generates the whistling sound.
Presentation
Laryngomalacia occurs in infants, peaking at 6 months. It presents with inspiratory stridor, a harsh whistling sound when breathing in. Usually this is intermittent and become more prominent when feeding, upset, lying on their back or during upper respiratory tract infections. Infants with laryngomalacia do not usually have associated respiratory distress.
It can cause difficulties with feeding, but rarely causes complete airway obstruction or other complications.
Disease Course and Management
The problem resolves as the larynx matures and grows and is better able to support itself, preventing it from flopping over the airway. Usually, no interventions are required and the child is left to grow out of the condition.
Rarely tracheostomy may be necessary. This involves inserting a tube through the front of the neck into the trachea, bypassing the larynx. Surgery is also an option to alter the tissue in the larynx and improve the symptoms.
Last updated August 2019