Bronchiolitis

Bronchiolitis is a chest infection that affects the bronchioles, the tiniest airways deep in the lungs. A virus makes these airways swell and fill with mucus, which makes it harder for a young child to breathe and to feed. It is one of the most common reasons babies are seen by a doctor or admitted to hospital in the colder months.

It is easy to confuse with a common cold at first, and many cases do stay mild. The illness is most common in babies under 1, and almost all cases happen before the age of 2, because their airways are small and block easily.

Bronchiolitis usually starts like a cold, with a runny or blocked nose and a mild cough. Over the next few days the cough can get worse and you may hear a wheeze (a high-pitched whistling sound) or notice your baby breathing faster than usual. Some babies have a slightly high temperature and feed less because the effort of breathing tires them out.

Symptoms are often at their worst around days 3 to 5, then slowly improve. The cough can carry on for up to 3 weeks even after your child is otherwise better.

Bronchiolitis is caused by a virus, most often respiratory syncytial virus (RSV). The same viruses spread easily through coughs, sneezes and on hands and surfaces, which is why cases rise in autumn and winter.

It is contagious. Frequent handwashing, keeping a sick baby away from very young or premature infants, and not smoking around your child all help reduce spread and lower the chance of a more serious illness.

A doctor can usually diagnose bronchiolitis just by examining your baby and listening to their chest, and by asking about the symptoms and how your baby is feeding. Tests are not normally needed for a mild case.

If a baby is very unwell, very young or struggling to breathe, the care team may check the oxygen level with a small sensor on the finger or toe, and sometimes take a sample from the nose or arrange a chest X-ray to rule out other problems.

Most babies can be cared for at home. Offer smaller feeds more often so your baby does not get too tired, keep them upright a little during feeds, and keep the room comfortable rather than too warm. Saline (saltwater) nose drops before feeds can help clear a blocked nose. You can give paracetamol or ibuprofen for a temperature if your child is distressed, following the dose for their age and weight.

Because the cause is a virus, antibiotics do not help. Cough and cold medicines are not recommended for young children. The most important job at home is to watch your baby's breathing and feeding closely.

Seek urgent medical help if your baby is breathing very fast, seems to be working hard to breathe, or you can see the skin sucking in around the ribs, below the ribs or at the base of the neck. Also get help straight away if your baby has taken much less than usual (around half their normal amount) over two or three feeds, or has had a dry nappy for 12 hours or more.

Call emergency services or go to the nearest emergency department immediately if your baby pauses or stops breathing, has long gaps between breaths, the lips, tongue or skin look blue or grey, your baby is very pale and floppy, or you cannot wake them or keep them awake. These are signs that a baby needs help quickly.

You cannot always prevent bronchiolitis, but you can lower the risk by washing hands often, cleaning toys and surfaces, keeping babies away from people with colds, and keeping your home and car completely smoke-free. Protection against RSV is also available for some babies; ask your child's doctor whether an RSV immunisation is recommended in your situation.

It also helps to keep newborns and premature babies away from large crowds during the winter peak, when these viruses spread most.

The outlook is very good. Most babies recover fully within about 2 weeks, although a lingering cough is common and can last up to 3 weeks. Serious complications are uncommon in otherwise healthy babies.

Babies born prematurely or with heart or lung conditions can become more unwell and are more likely to need hospital care, so they should be watched especially closely. Some children who have had bronchiolitis go on to have episodes of wheezing with later colds, which usually settles as they grow.