Bronchiolitis

Bronchiolitis is a common respiratory infection that affects babies and young children. It occurs when the smallest airways in the lungs, called the bronchioles, become infected and inflamed, leading to a build-up of mucus. This makes it harder for the child to breathe as the amount of air entering the lungs is reduced.

It is estimated that a third of infants in the UK develop bronchiolitis in their first year of life, and 90% of those who do are less than 9 months old. This is because babies have smaller airways, and their lungs and immune systems may not yet be fully developed. Premature babies, those born with lung or heart diseases, and those with weakened immune systems are most at risk of the condition, and may need special care if they develop it.

Bronchiolitis is most commonly caused by an airborne virus called respiratory syncytial virus (RSV), which is passed on through direct contact and through airborne droplets spread by coughing and sneezing. The condition usually occurs in winter.

Many of the symptoms of mild bronchiolitis are similar to those of a common cold, including a stuffy nose, mild fever and a cough. There is no medicine that can kill the virus, but the infection usually clears up on its own, and treatments can be used to make children more comfortable. In more severe cases, children may need to be hospitalised if they are having difficulty breathing or are refusing to eat and drink.

The early symptoms of bronchiolitis are similar to those of a common cold. They include:

• a blocked or runny nose,
• mild fever, and
• a loss of interest in feeding.

After two to three days the symptoms tend to peak, and may become more severe. Your child may develop:

• rapid or shallow breathing,
• a rasping and persistent dry cough, and
• a faster than normal heartbeat.

These symptoms can be very worrying for parents, but most cases of bronchiolitis are not serious. However, if your child is showing symptoms of bronchiolitis and they are under 12 weeks old, or they have an underlying health problem such as a congenital (present from birth) lung or heart condition, you should see your GP as soon as possible.

In all cases, you should watch your child closely for any changes to their symptoms and contact your GP if you are at all worried. You should also see your GP if your child develops any of the following symptoms:

• increased difficulty breathing,
• refusal to feed (your child has taken less than half of their normal feeds over 2-3 feeds),
• no wet nappy for 12 hours or more,
• vomiting,
• a high temperature (over 38C or 100.4F), and
• tiredness or irritability.

While it is unusual for children to need hospital treatment for bronchiolitis, the symptoms can get worse very quickly. Dial 999 for an ambulance if your child develops any of these symptoms:

• difficulty breathing or exhaustion from trying to breathe (you might see the muscles under your baby's ribs sucking in with each breath, and they may be pale and sweaty),
• rapid breathing rate of more than 40 breaths a minute,
• breathing stops for more than ten seconds at a time (known as recurrent apnoea), and
• skin begins to turn ashen or blue, especially around the lips or fingernails (known as cyanosis).

If your child's bronchiolitis is not severe, the infection usually lasts about a week before clearing up on its own. Most children recover fully within two weeks, although up to half may have a recurrent cough or wheeze for some time afterwards. However, permanent damage to the airways is very rare.

Most cases of bronchiolitis are caused by the respiratory syncytial virus (RSV). This virus thrives in the human nose and throat, and causes symptoms to appear a few days after the initial infection. Other examples of viruses that may cause bronchiolitis are the parainfluenza virus, and the influenza (flu) virus.

Viruses are spread through either direct contact or through tiny airborne droplets of liquid, passed on through coughing and sneezing. Children who have had bronchiolitis can still be infectious for up to three weeks after having the condition, even after their infection has cleared.

Once the virus enters the respiratory system through the windpipe (trachea), it makes its way down to the smallest airways in the lungs, which are called the bronchioles. The infection causes the bronchioles to become swollen and blocked with mucus, which hinders breathing. Babies and young children have tiny, often under developed airways, which is what makes them prone to bronchiolitis.

Children who are born with lung or heart diseases, those who are born prematurely, and those with weakened immune systems are more at risk of developing bronchiolitis. There is also some evidence that babies who are never breast fed, and those that are exposed to cigarette smoke may be more susceptible to the condition.

If you think your child may have bronchiolitis, you should take them to see your GP, or dial 999 for an ambulance if they have any of the following symptoms:

• difficulty breathing or exhaustion from trying to breathe (you might see the muscles under your baby's ribs sucking in with each breath, and they may be pale and sweaty),
• rapid breathing rate of more than 40 breaths a minute,
• breathing stops for more than ten seconds at a time (known as recurrent apnoea), and
• skin begins to turn ashen or blue, especially around the lips or fingernails (known as cyanosis).

If you see your GP, they may check for wheezing and listen to your child's lungs using a stethoscope. They may also check for signs of dehydration if your child has been vomiting or refusing to eat and drink. These include sunken eyes, a dipped fontanelle in babies (the soft spot on the top of the head), dry mouth and skin, lethargy and producing little or no urine.

In some cases, your GP may want to do further tests to confirm a diagnosis, such as a chest x-ray, a mucus sample test or a blood test.

Chest x-ray

This is used to check for swelling of the airways in your child's lungs. It can also be used to check for signs of pneumonia, which can develop alongside bronchiolitis in some rare cases, and can reveal whether your child has inhaled something small that may be affecting their breathing.

Mucus sample test

Your GP may use a swab to collect a sample of mucus from your child's nose, in order to determine which virus is causing your child's bronchiolitis.

Blood test

Your GP may need to check if your child's white blood cell count is up, which shows whether your child's body is fighting an infection. A blood test can also determine whether the level of oxygen in your child's blood has gone down.

There is no medicine that can kill the viruses that cause bronchiolitis and most cases clear up on their own within two weeks. However, there are treatments that can ease your child's symptoms and make them more comfortable.

If your child's bronchiolitis is mild, you can treat them at home as outlined below.

• Drink plenty of fluids - make sure that your child drinks plenty of water, or fruit juice, in order to avoid dehydration. They may drink more slowly than usual because they are congested, so try giving them smaller feeds more frequently.
• Paracetamol syrup - this is available over-the-counter (OTC) from pharmacies without prescription, and it can ease a fever, sore throat and pain, which will help the child to feed and sleep normally. Children under 16 years of age should not be given aspirin.
• Saline nasal drops - are also available from pharmacies and can help to ease your child's congestion.

If your child's bronchiolitis is more severe, your GP may recommend a bronchodilator drug, which aids your child's breathing by opening up the airways in their lungs.

On average, 2 in 10 children with bronchiolitis are admitted to hospital. This is usually just a precaution because they are not eating and drinking enough. However, premature children, and those with an underlying health problem, such as a lung condition or weakened immune system, are also likely to need treatment in hospital.

If your child is admitted into hospital, they will probably be given humidified oxygen to maintain the oxygen levels in their blood, through either a headbox or through tubes inserted into their nose. The doctors may use antiviral drugs, and fluids may be given intravenously (directly into the vein) to avoid dehydration. In rare cases, your child may need artificial ventilation to help them breathe.

There are several complications associated with bronchiolitis. These may include:

• difficulty breathing,
• cyanosis (an ashen or blue tinge to the skin caused by lack of oxygen),
• dehydration,
• fatigue, and
• severe respiratory failure (an inability to breathe unaided).

If any of these complications occur, it is likely that your child will need treatment in hospital.

There are also a number of other factors that may complicate cases of bronchiolitis.

Underlying health conditions

If your child was born with a health problem such as a heart or lung disease, or a weakened immune system, their symptoms of bronchiolitis may come on very rapidly and quickly become severe. The infection can also make any symptoms of your child's underlying health problem worse.

Pneumonia

In rare cases, bronchiolitis can be accompanied by bacterial pneumonia which infects the lungs. If this happens, the pneumonia will need separate treatment.

Asthma in later life

Little is known about how cases of bronchiolitis relate to the development of asthma. However, if your child has repeated bouts of bronchiolitis, there may be a chance that they are more likely to develop asthma in later life as a result.

The viruses that cause bronchiolitis are extremely common and easily spread, so preventing the condition altogether is not possible. There is no vaccine, but there are steps you can take to help prevent your child from catching bronchiolitis, or if they already have it, to help prevent it from spreading further. You should:

• try to cover your child's nose and mouth when they cough or sneeze,
• use disposable tissues rather than cotton handkerchiefs, and throw them away as soon as they are finished with,
• wash your and your child's hands frequently, especially after touching their nose or mouth, or after feeding,
• wash and dry eating utensils after use,
• keep infected children at home, and
• keep newborn babies away from people with colds or flu, especially in their first two months or if they are born prematurely.

If your child is very premature, or if they are born with a heart or lung condition, it may be possible to for them to have monthly antibody injections in order to limit the severity of a possible bout of bronchiolitis. See your GP to find out more.

As well as treating your child's bronchiolitis at home, try following these tips to make your child more comfortable:

Humidify the air

If you have access to an air humidifier, try using it to moisten the air which can ease your child's cough. Alternatively, run the shower or bath for several minutes to steam up the room, then sit in there with your child for about 15 minutes. This may even help to ease a coughing fit. Your home should be a comfortable temperature, but do not make it too warm as this will dry out the air.

Keep your child upright

Try putting your child in their car seat in order to keep them upright, as this will make their breathing easier. If they need to nap while in the seat, make sure that your child's head will not fall forward by supporting it with something, such as a rolled up blanket.

Keep a smoke free environment

Cigarette smoke can aggravate your child's symptoms, so if you smoke, do not do so around your child. Passive smoking can affect the lining of your child's airways, making them less resistant to infection, so keeping smoke away from your child may even help to prevent future bouts of bronchiolitis.