Laryngomalacia is the most frequent cause of noisy breathing (stridor) in infants and children. It is the most common congenital anomaly (birth defect) of the voice box (larynx).
Laryngomalacia is best described as floppy tissue above the vocal cords that falls into the airway when the infant breathes in. The cause of laryngomalacia and the reason why the tissue is floppy are unknown. Most likely, the part of the nervous system that gives tone to the airway is underdeveloped.
Infants with laryngomalacia have intermittent noisy breathing when inhaling, also called inspiratory stridor. This noise may either improve or worsen depending on the infant's sleeping or lying position.
Inspiratory stridor very often becomes worse with agitation, crying, excitement, feeding, or positioning/sleeping on the back. These symptoms are often present at birth, and usually occur within the first 10 days of life. However, the noisy breathing of laryngomalacia may begin any time during the first year.
Symptoms will often increase or worsen over the first few months after diagnosis, usually between four to eight months of age. Most infants with laryngomalacia outgrow the noisy breathing by 12 to 18 months of age.
Other symptoms that can be associated with laryngomalacia include:
Laryngomalacia can be mild, moderate or severe. About 99 percent of infants with laryngomalacia have mild or moderate laryngomalacia.
Mild laryngomalacia: Infants with mild laryngomalacia have noisy breathing (inspiratory stridor). There is no significant airway obstruction, no feeding difficulties, or other symptoms associated with laryngomalacia. The noisy breathing is annoying to caregivers, but does not cause other health care problems.
Infants with mild laryngomalacia usually outgrow the stridor by 12 to 18 months of age. Even though your infant may have mild laryngomalacia, it is still important to watch for signs and symptoms of worsening laryngomalacia.
Moderate laryngomalacia: Infants with moderate laryngomalacia have noisy breathing or inspiratory stridor. They may also have:
Infants with moderate laryngomalacia usually outgrow the stridor by 12 to 18 months of age, but may require treatment for gastroesophageal reflux. Stomach acid, if it reaches the upper part of the esophagus and voice box, can cause swelling of the floppy tissue above the vocal cords. Very often, infants with moderate or severe laryngomalacia need oral medications to treat gastroesophageal reflux.
Even though your infant may have moderate laryngomalacia, it is still important to watch for signs and symptoms of worsening laryngomalacia.
Severe laryngomalacia: Infants with severe laryngomalacia have noisy breathing or inspiratory stridor. They may also have:
Only one percent of infant laryngomalacia are severe cases, and these usually require surgery.
Flexible laryngoscopy: This technique is needed to confirm the diagnosis of laryngomalacia. A lighted scope or laryngoscope is passed through the nose or mouth. The doctor looks at the tissue above the vocal cords to determine if it is floppy. The upper airway is also checked for any other problems that may be contributing to the noisy breathing.
Neck and chest X-rays: Some infants with laryngomalacia also have additional airway problems that may contribute to the noisy breathing. Neck and chest x-rays look for other problems in the upper airway, windpipe or trachea, chest, and lungs. Additional tests may be recommended if the x-rays are abnormal.
Microlaryngoscopy and bronchoscopy (ML&B): ML&B is performed in the operating room under general anesthesia. The doctor looks at the voice box and windpipe with a lighted scope. The area is checked for any airway problems that may be contributing to the noisy breathing. ML&B may be recommended if the x-rays are abnormal or other airway problems in addition to laryngomalacia are suspected.
Impedance probe: There is a high incidence of gastroesophageal reflux in infants with moderate or severe laryngomalacia. Oral medications may be prescribed or an impedance probe may be recommended to check for the degree of gastroesophageal reflux. An impedance probe is a small tube placed through the nose and into the esophagus. The tube is connected to a measuring device that records the number of times acid leaves the stomach and reaches the esophagus. This test measures the acid in the upper esophagus near the throat and the lower esophagus just before the stomach. The impedance probe is placed while taking an x-ray. Infants are hospitalized overnight for this test.
Infants with severe laryngomalacia usually need surgery. A supraglottoplasty is usually recommended. The floppy tissue above the vocal cords is trimmed in the operating room under general anesthesia. The surgery is performed through the mouth. A breathing tube is usually left in place, and infants are monitored in the Pediatric Intensive Care Unit overnight. The surgery may not make the noisy breathing go away completely, but should lead to much improvement. In rare cases, some infants may need further surgery.