Laryngomalacia

What is laryngomalacia?

Laryngomalacia is a condition seen in small babies in whom the larynx is particularly soft and limp, possibly because normal development of the supporting tissues has been slow or delayed.

There are several types - the mildest may cause no problems, while the most severe can be associated with other abnormalities of the respiratory tract, and with neuromuscular and gastroenterological problems.

Symptoms

Until the larynx becomes stronger, problems can arise for several reasons:

• The soft limp tissues of the larynx can collapse as the baby breathes in. This interrupts the flow of air and causes noisy breathing, with a sound called stridor, which is a sign of obstructed air flow – in fact laryngomalacia is the commonest cause of stridor in babies. It may be worse if the baby has a respiratory infection.
• In some children, laryngomalacia can interfere with feeding. The effort required to draw air in through the obstructed airway can cause reflux of food from the stomach back up into the oesophagus or gullet.
• There may be other ear, nose and throat problems, and rarely problems with the lungs. Low oxygen levels may disrupt normal growth.

Causes and risk factors

Laryngomalacia is thought to be the result of abnormally slow maturation of the tissues of the larynx, possibly because of genetic factors. This simply means that at birth the baby’s respiratory tract isn’t developed and string enough to cope with the mechanical demands of drawing breath.

Although doctors believe there's a link between laryngomalacia and gastro-oesophageal reflu, there isn't a single common mechanism to link these two problems, so several theories exist. In some patients with laryngomalacia, reflux may be the primary cause of their airway problems. In others, it's an additional factor on top of neurological or anatomical abnormalities.

Reflux is common in babies less than one year old, because the muscular valve at the entrance to the stomach (which holds food in the stomach) may be weak in small infants.

Research suggests that a very large number, if not all, of babies with laryngomalacia also have reflux of gastric acid and digestive enzymes up to the pharynx (back of the throat). This may have detrimental effects on the larynx and tracheobronchial tree (air passages into the lungs). This may cause persistent swelling (oedema) of the larynx lining, which is common in children with laryngomalacia.

There's no consensus yet about managing this link, but it makes sense to think simple treatments to control reflux could help resolve the laryngomalacia more quickly, too. More interventional treatments such as surgery, with all their inherent risks, are best avoided if possible.

Treatment and recovery

Both laryngomalacia and gastro-oesophageal reflux are common in small babies and in the vast majority of cases the condition resolves with time as the child grows and matures, leaving no lasting problems. If the baby has a normal cry, normal weight gain and normal development, with just an odd noise when it breathes in, then specific treatment is not likely to be needed.

In most children the noisy stridor has gone by the age of 2. Occasionally the problem persists for longer, and very rarely into adulthood. In these case, symptoms are most likely to reappear during a respiratory infection or sometimes with exercise.

Simple treatment, especially of the reflux, is usually enough to keep on top of symptoms:

• Changing the child's sleeping position. Raise the end of the cot by a few inches to let gravity help keep stomach contents down.
• When children are awake, prop them in a baby chair rather than letting them lie down on the ground.
• Thicken their feed with rice flour, cornflour or carob flour (but talk to your health visitor about this first).
• If your baby is weaned, introduce more solids to the diet.

Your GP can also prescribe several treatments that may help to restrict the damage of reflux, by increasing the muscular tone of the gullet or reducing acid production in the stomach.

If there are other ear, nose or throat problems, such as laryngitis, otitis or sinusitis, some studies suggest that actively treating the reflux may help to resolve them.

In more severe cases, further investigations such as laryngoscopy or bronchoscopy may be needed, or the baby may need treatment with oxygen or even a tracheotomy (a hole made through the neck into the air passage) to improve breathing.