Bronchiolitis in Newborns

What is bronchiolitis?

Bronchiolitis is a serious medical condition of the respiratory tract that commonly affects newborns and young children.1 Bronchiolitis occurs when the small airways of the respiratory tract, the bronchioles, become infected with a virus; resulting in swelling of these airways and the buildup of mucus. The combination of the swelling and mucus buildup in the airways causes difficulty breathing. Bronchiolitis most commonly occurs in the winter months.1,3  Bronchiolitis can be easily treated at home, however, a small number of cases of bronchiolitis in infants may require hospital care.2 

Causes of bronchiolitis in children

Bronchiolitis is caused by a wide range of viruses, most specifically, the influenza virus, rhinovirus, and respiratory syncytial virus.3 The influenza virus is the viral infection that causes the flu, rhinovirus causes the common cold, and the respiratory syncytial virus (RSV)  is a common season infection that, in cases of severe infection, can lead to bronchiolitis and pneumonia.3 5  These viruses are highly contagious as they spread from person to person via respiratory droplets in the air and oral and nasal secretions.3 Severe infection by any of the three viruses can cause bronchiolitis in children. RSV especially infects virtually all children by the time they reach the age of two years old, as outbreaks of RSV occur every winter.2 

Risk factors

There are several risk factors associated with bronchiolitis in newborns:

  • Age: Bronchiolitis mostly affects children under the age of two years old, however, newborns are at the greatest risk and most susceptible to bronchiolitis as their immune systems have not fully developed enough to fight off the viral infection, and their lungs are still in development.2 
  • Premature birth: Premature babies are at a higher risk of various health conditions as their immune systems are not as fully developed as full-term babies. As a result, they would also be at greater risk of bronchiolitis.2
  • Preexisting Heart Condition: Having a preexisting heart condition puts one at greater risk of bronchiolitis as the interconnection between the heart and respiratory tract can make the respiratory system more susceptible to viral infections.2 6 
  • Formula-fed Babies: Babies who are breastfed are able to reap better immune protection from the mother. Research has continuously proven that breastfed babies have stronger developed immune systems than formula-fed babies. As a result, formula-fed babies are typically at higher risk of bronchiolitis.2
  • Being in Childcare Settings: Children that go to daycares, preschool, or any other type of environment with lots of children are at higher risk of bronchiolitis as viruses are easily spread between children.2
  • Having Siblings that Attend School: Having siblings that attend school is a risk factor of bronchiolitis as siblings can spread the viral infection that they would have caught at school to children at home.2 
  • Tobacco Smoke Exposure: Exposure to tobacco smoke has adverse effects on the respiratory system, especially in children. Damage or irritation to the respiratory system can make an individual more susceptible to bronchiolitis.2

Symptoms of bronchiolitis in children

Symptoms of bronchiolitis vary from child to child, however, there are significant symptoms to look out for. According to the NHS, bronchiolitis’ initial symptoms are similar to the symptoms of the flu and the common cold.6 These symptoms include runny nose, cough, sneezing, and raised body temperature. Unique symptoms of bronchiolitis in children include quicker breathing, wheezing, and being easily irritable. As bronchiolitis progresses, symptoms may worsen leading to difficulty swallowing and suckling (which may lead to reduced appetite), blue or grey colouring at the lips, and fatigue.3 When severe symptoms arise, you should contact a healthcare provider or emergency services immediately.  It can take up to three weeks for symptoms to fully clear up, days 3 to 5 are typically the days most children experience the most severe symptoms of bronchiolitis.6

Is bronchiolitis contagious?

The viruses that cause bronchiolitis, RSV, rhinovirus, and influenza, are highly contagious. Young children are easily able to spread these viruses to each other. Infection with one of the viruses can lead to bronchiolitis if the virus infects the bronchioles (small respiratory airways).3 This is why it is typically recommended to have children infected with bronchiolitis stay away from other children to prevent the spread of these viruses.3

How long do symptoms of bronchiolitis last?

According to The Cleveland Clinic, it may take anywhere from two to eight days for symptoms of bronchiolitis to emerge.5 It can take up to three weeks for symptoms of bronchiolitis to fully clear up. However, days 3-5 of the condition are typically when symptoms are at their worst. Bronchiolitis and its symptoms usually clear up at home without the need for serious medical intervention. However, the occurrence of severe symptoms does require immediate medical attention. 

Differences between bronchitis and bronchiolitis

Bronchitis and bronchiolitis have several significant differences that one can use to differentiate the two conditions. Both bronchitis and bronchiolitis are caused by a viral infection and have similar symptoms to each other as well as other respiratory conditions such as pneumonia.3 However, the affected area of the respiratory system in bronchitis is the bronchi, the larger respiratory airways. Bronchiolitis affects the bronchioles, the smaller respiratory airways.3 Bronchitis can affect those of all ages, especially older adults, while bronchiolitis typically affects young children.3 Therefore, the main difference between the two conditions is the area of the respiratory tract that they affect. 

Diagnosing bronchiolitis in children

Chest X-rays

Chest X-rays are not commonly used to diagnose bronchiolitis as doctors are usually able to identify bronchiolitis using a stethoscope to listen to the lungs. Chest X-rays can confirm inflammation of the bronchioles to identify bronchiolitis. However, recent research suggests that using chest X-rays to diagnose bronchiolitis may actually be harmful due to the exposure to radiation, chance of incorrect diagnosis, and emotional stress it places on families.7 

Blood tests 

Blood tests may also be used to diagnose bronchiolitis by examining the patient’s white blood cell count.7 White blood cells are the blood cells that are responsible for fighting infection - an increase in the white blood cell population in a patient shows that the body is fighting an infection. An increase in white blood cell count and a decrease in oxygen levels can lead to the confirmation of the diagnosis of bronchiolitis.7

Pulse oximetry

Pulse oximetry is a diagnosis test that measures a patient’s oxygen levels in the blood.8 While it is also used as a diagnostic tool, it is also used to monitor a patient’s oxygen level when in the hospital with severe acute bronchiolitis.8 

Swab of the nose and throat

A swab of the nose and throat is another diagnostic tool that healthcare professionals may use to diagnose a child with bronchiolitis. It involves swabbing the nose and throat for mucus collection, the mucus is then tested in a lab for any of the viruses that can cause bronchiolitis.7

Treating bronchiolitis in children

Why do some children need a hospital stay?

Although bronchiolitis is usually treatable at home, some children with bronchiolitis require a hospital stay. These children may require oxygen therapy due to reduced oxygen levels due to the inflamed bronchioles, specific IV fluids to prevent severe dehydration, and other specific medical interventions to recover from the condition. This may be due to a weakened immune system, having other underlying conditions, or experiencing any of the severe symptoms of bronchiolitis.7 

Care at home for children

Generally, most children with bronchiolitis can be treated at home. There are several remedies that can make recovery for children with bronchiolitis more comfortable. 

  • Administering children’s paracetamol to children aged two months and older or administering ibuprofen to children aged three months and older6
  • Saline drops for a blocked and/or runny nose6
  • Keeping the child well hydrated6 Making sure the child remains upright to not further disturb breathing6

It is important to remember that there is not one specific treatment for bronchiolitis as the mucus buildup and inflammation causes most of the condition’s symptoms to clear up on their own. However, children with severe symptoms should seek serious medical attention as complications may arise.


Most children are able to make a full recovery from bronchiolitis three weeks following the emergence of symptoms.3 However, the ultimate duration of full recovery will vary from person to person. Recovery is also dependent on how hydrated patients remain during the height of the condition, as it has been noted that those who remain hydrated over the course of the condition usually recover following 21 days .3


If severe bronchiolitis arises and is left untreated, it can lead to several complications. Cyanosis, which is characterised by blue pigmentation of the skin, occurs due to a lack of oxygen.2 The inflamed bronchioles can cause reduced oxygen intake in the respiratory system, thus leading to reduced oxygen delivery to the surrounding tissues.2 Reduced oxygen delivery to the tissues results in low oxygen levels which can lead to respiratory failure. Respiratory failure is a very serious medical condition which requires serious medical attention and, as a result, the occurrence of severe bronchiolitis symptoms requires immediate medical attention.2 


There are several different methods to ease a child’s treatment and recovery from bronchiolitis. Although bronchiolitis can typically be treated at home, one should continuously monitor the progression of these symptoms as severe symptoms can lead to serious complications such as cyanosis, low oxygen delivery, and respiratory failure.2 


As bronchiolitis is spread through respiratory droplets and oral and nasal secretions of any person infected with a virus, the most effective way to prevent the occurrence of the condition is frequent handwashing.6 Frequent handwashing ensures that the viruses are washed and killed off the skin to reduce the spread of bronchiolitis-causing viruses. Frequent disinfecting of repeatedly touched surfaces and toys can also prevent bronchiolitis, as respiratory droplets and oral and nasal secretions can easily lie on these surfaces.6 Isolating newborn kids from anyone with the flu, cold, or any other viral infections can also prevent the occurrence of bronchiolitis as these viral infections can lead to bronchiolitis in young children.6

When to contact a doctor

Whether or not you suspect your child to have bronchiolitis, you should contact a doctor:

  • If your child has a cold and the cold progressively gets worse
  • Suddenly experiences reduced appetite6
  • The sudden raised temperature of 38°C or higher6
  • Lethargy6
  • Blue pigmentation of the skin (Cyanosis)
  • Wheezing2


Bronchiolitis is a medical condition characterised by the buildup of mucus and inflammation of the bronchioles.1 Bronchiolitis is caused by a viral infection of either RSV, influenza virus, or rhinovirus.3 The condition is most common in newborns and young children due to the easy spread of the viruses that cause the condition. Although, it is usually easily treated at home, the occurrence of severe symptoms requires serious medical attention. Bronchiolitis can be prevented by continuous disinfecting of shared surfaces and toys to prevent the spread of the viruses and isolating newborns from ill people. The condition usually clears up after three weeks if the affected individual remains hydrated .5 


  1. Palta A. Bronchiolitis [internet]. 2020  [cited 2022 July 20]. Available from:
  2. Mayo Clinic. Bronchiolitis [internet]. 2020 January 15 [cited 2022 July 20]. Available from:
  3. Cleveland Clinic. Bronchiolitis [internet]. 2020 May 30 [cited 2022 July 20]. Available from:
  4. Intermountain Healthcare. Rhinovirus [internet]. 2022 [cited 2022 July 20]. Available from:
  5. Cleveland Clinic. Respiratory Syncytial Virus in Children and Adults [internet]. 2020 February 04 [cited 2022 July 20]. Available from:
  6. NHS. Bronchiolitis [internet]. 2022 April 13 [cited 2022 July 20]. Available from:
  7. Jung J. Respiratory Syncytial Virus Infection in Children with Congenital Heart Disease: Global Data and Interim Results of Korean RSV-CHD survey. Korean Journal of Pediatrics [internet]. 2011 May 31 [cited 2022 July 20]; 54(5): 192-196.  Available from:
  8. Hendaus M, Jomha F, Alhammadi A. Pulse Oximetry in Bronchiolitis: is it needed?. Therapeutics and Clinical Risk Management [internet]. 2015 October 12 [cited 2022 July 20]; 11(1): 1573-1578. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Brianna Jacobs

Bachelor of Science - BS, Biomedical Sciences, General, University of Birmingham, England
Brianna is a Second Year Biomedical Science Student who experienced Medical Writing Intern.

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