Subglottic cysts often result from intubation or ventilator use. The period of intubation may be relatively brief but after several hours, days or even months, noisy breathing (stridor) may develop with signs of upper airway obstruction. Most cases of subglottic cysts occur in premature infants, as the need for intubation in these children is more common.

The subglottis, or lower part of the larynx, is located just below the vocal cords. Because these cysts partially block the airway or put pressure on the vocal cords, signs and symptoms of subglottic cysts can include:

• Noisy breathing (stridor): The cysts may interfere with the airway, causing a noisy raspy or rattling sound when breathing in and/or out.
• Trouble breathing: Breathing can be difficult depending on the degree of blockage caused by the cyst. If the blockage is too large, it can be fatal.
• Recurrent croup: The narrower airway passage causes a barking sound when the child coughs.
• Hoarseness: The cysts may add pressure to the vocal cords, causing hoarseness.
• Obstructive apnea: Breathing may stop from time to time during sleep due to the blockage in the airway caused by the cyst.

Subglottic cysts can be misdiagnosed as laryngomalacia, asthma, croup, or other diseases and conditions. It is important, however, that a diagnosis be made because if the blockage of the airway is severe enough, it can be fatal. Subglottic cysts may be diagnosed with any of the following tests:

• Endoscopy. A flexible fiber optic tube passed through the child’s mouth. The doctor will look for cysts along the subglottis.
• Neck X-ray. An X-ray allows the doctor to see if one or more cysts are present, or if the child’s symptoms are being caused by some other reason such as a swallowed foreign object.
• Flexible laryngoscopy. A flexible tube that allows the doctor to see the throat better. Laryngoscopy allows the doctor to see if one or more cysts are present, or if the child’s symptoms are being caused by some other reason such as laryngomalacia.

Treatment depends on the following:

• The number of cysts
• The size of the cyst(s)
• The location of the cyst(s)
• The degree of blockage

During an endoscopy procedure, your doctor may deflate the cyst, allowing fluid to drain out of it. You will likely stay overnight in the hospital to make sure the airway remains open and that the child can breathe easily. An endoscopy may be done a few months later to ensure the cysts don’t return.

Cysts may recur. There is a risk of narrowing of the airway below the vocal cords (subglottic stenosis) as a result of the cysts. It is important for these children to have long-term follow-up monitoring and care.

Call 911 immediately if your child:

• Cannot breathe
• Turns blue
• Is unconscious

Call your doctor if your child:

• Develops stridor
• Has trouble breathing