1 What is Bronchiolitis?

Bronchiolitis is an acute inflammatory lung condition, which is more severe in young children and infants, although it may occur in persons of any age.

It usually affects children below the age of 2 with a peak incidence in infants of the age between 3 and 6 months. It causes swelling and mucus buildup or congestion in the small air passages (bronchioles) of the lung.

Bronchiolitis is almost always occurs due to a virus, most commonly respiratory syncytial virus and human metapneumovirus. It develops typically during the winter months.

Bronchiolitis begins with initial symptoms that are similar to those of a common cold but then progresses to

Symptoms of bronchiolitis may last upto several days to weeks, sometimes even a month. Generally, acute bronchiolitis that is common during the first year of life is self-limiting, and children improve with supportive care at home.

A very small percentage of children may require hospitalization.

2 Symptoms

Some children with bronchiolitis have only few, mild symptoms during the initial days.

The signs and symptoms seem to be similar to a mild upper respiratory infection, and include:

  • Runny nose
  • Stuffy nose
  • Cough
  • Mild fever (not always)
  • After about 2-3 days, children develop difficulty in breathing or shortness of breath and wheezing (whistling sound when breathing out).

Many infants may also develop an ear infection (otitis media). Other symptoms include:

  • Bluish discoloration of skin because of lack of oxygen (cyanosis)
  • Fatigue
  • Muscles surrounding the ribs retract as the child breathe in air
  • Infant's nostrils become wide while breathing
  • Rapid breathing rate (tachypnea)

When to see a doctor

Consult your child's doctor if your child refuses to eat and develops respiratory problems with more rapid and labored breathing. This is very important if your child is below 12 weeks of age or has other risk factors for bronchiolitis — including premature birth or a heart or lung disorder.

The development of following signs and symptoms need immediate medical attention:

  • Vomiting
  • Shallow breathing with a rapid breathing rate — more than 60 breaths per minute
  • Lips and fingernails turn bluish
  • Lethargy
  • Refusing to drink enough fluids, or breathing very fast to eat or drink
  • Wheezing sounds that are audible
  • Ribs that sink inwards when infant breathes in

3 Causes

Bronchiolitis is caused due to infection of the bronchioles from viruses such as:

  • respiratory syncytial virus (RSV),
  • human metapneumovirus,
  • parainfluenza virus,
  • influenza virus,
  • adenovirus.

RSV is a common virus that infects about every child by the age of 2. Seasonal outbreaks of RSV infection occur more often during every winter.

Bronchiolitis is a highly contagious condition, and the virus spreads from one person to the other through direct contact or breathing in with airborne droplets and nasal secretions that get released into the air when a sick person sneezes or coughs.

One can also contract this condition by touching shared toys, utensils or towels, and then touching your nose or mouth.

This infection causes inflammation of the bronchioles, and as mucus accumulates in these air passages, it might be difficult for the air to flow freely into and out from the lungs.

4 Making a Diagnosis

To diagnose bronchiolitis, you must take your child to his or her physician, who will ask a set of questions and perform necessary testing.

You may consult your family doctor or your child's doctor. Here is some information to help you get ready for your appointment, and what to expect from your doctor.

What you can do

Write down the following information:

  • Symptoms your child is having, including those that seem unrelated to an upper respiratory infection, and when they started.
  • Key personal information, such as whether your child was born prematurely or presence of a heart or lung problem.

Write down questions to ask your doctor

Some basic questions to ask your doctor include:

  • What is the most likely cause for my child's symptoms?
  • Are there any other possible causes?
  • Does my child need any diagnostic tests?
  • For how long do the symptoms last?
  • Does my child's infection spread?
  • What is the best course of action?
  • What are the alternatives to the primary approach that you have suggested?
  • Does my child need medications? If so, is there a generic alternative to the medicine you have prescribed?
  • What can be done to make my child feel better?

What to expect from your doctor

Be prepared to answer these questions your doctor may ask:

  • When did your child first begin experiencing symptoms?
  • Have your child's symptoms been continuous, or occasional?
  • How severe are your child's symptoms?
  • Is there anything that seems to improve or worsen your child's symptoms?

What you can do in the meantime

If your child has a fever, you can give acetaminophen (Tylenol, others) or ibuprofen (Children's Advil, Children's Motrin), only if your child is above the age of 3 months. Make sure your child drinks lot of fluids to prevent dehydration. Keeping your child upright and the air in the room moist using a humidifier may help ease congestion.

Tests and X-rays are generally not required to diagnose bronchiolitis. The doctor identifies the problem by observing your child and listening to your child's breathing pattern with a stethoscope. Several visits may be needed distinguish this condition from a cold or flu.

If your child is at a higher risk for severe bronchiolitis, if the symptoms are getting worse or if another problem is suspected, your doctor may order the following tests:

Chest X-ray

Your doctor may order a chest X-ray to rule out the signs of pneumonia.

Mucus sample test

Your doctor will collect your child's mucus sample to test for the virus causing bronchiolitis. The collection is done using a swab or a suction catheter that can be gently inserted into your child's nose.

Blood tests

Occasionally, blood tests may be done to determine your child's white blood cell count. An increase in the white blood cells is a sign of an infection. A blood test can also check whether the level of oxygen has decreased in your child's bloodstream.

An alternative test to check for the blood oxygen levels is an oximeter that is placed over the finger.

Your doctor may ask you about signs of dehydration, whether your child has been refusing to drink or eat or has been vomiting. Signs of dehydration include sunken eyes, dry skin and mouth, sluggishness, and minimal or no urinary output.

5 Treatment

The goal of treatment of bronchiolitis is to achieve relief from symptoms such as breathing difficulty and wheezing.

Most cases of bronchiolitis may be treated with supportive care at home. In severely ill children, antiviral drugs may be considered.

At home, you can follow these measures to relieve your child's symptoms:

  • Make sure your child drinks lot of fluids.
  • For children younger than 1 year, breast milk or formula may be given.
  • Consider use of saline nasal drops or suctioning with a bulb to relieve nasal congestion.
  • Be alert to changes such as troubled breathing. Expect the condition to last atleast for a week to a month.
  • Use a humidifier to moisten the air as breathing in moist air helps in loosening the sticky mucus.
  • Ensure your child gets adequate rest.
  • Avoid smoking in the house, car or anywhere when your child is nearby.


Although drugs that open up the airways (bronchodilators) have not been proven to be helpful, your doctor may try a nebulized albuterol treatment to see whether it is effective.

As bronchiolitis is caused by viruses, antibiotics are not effective against it unless your child has an associated bacterial infection, such as pneumonia.

Hospital care

A small percentage of children with breathing difficulty may need to stay in a hospital, where the treatment includes humidified oxygen therapy to maintain enough oxygen levels in the blood and intravenous administration of fluids to prevent dehydration.

In severe breathing problems, a tube may inserted directly into the windpipe in order to help your child breathe.

6 Prevention

Most of the times, bronchiolitis cases are not preventable as the viruses that cause this condition are ubiquitous and are commonly present in our environment.

However, as bronchiolitis spreads from person to person, paying attention to frequent handwashing, especially when around infants is one of the best methods that helps in the prevention and spread of this viral infection.

When you have a cold, wear a face mask and wash your hands before touching your baby. Let your child stay at home during the illness so as to prevent spread of infection to others.

Other measures that can effectively curb the spread of the infection include:

  • Restrict your child's contact with people, especially if they have a fever or cold.
  • Avoid exposure of newborn infants to people with colds at least in the first two months of life.

Get your child vaccinated against flu

An annual influenza shot is recommended for every child older than 6 months. Although it cannot prevent the commonest cause of bronchiolitis (respiratory syncytial virus), it will avoid a severe influenza infection.

Keep your bathroom and kitchen countertops clean

Be particularly careful if anyone in your family has a cold. A solution of bleach and water made by mixing a tablespoon of bleach per gallon of cool water (14.8 milliliters per 3.8 liters) can be used as a disinfectant. Avoid mixing any other chemicals, as it can result a toxic chemical reaction. Always store mixtures made at home in a clearly labeled container and out of the reach of young children. It is better to discard unused mixtures.

Use tissues only once

Do not reuse the tissues and discard used ones promptly, and then wash your hands or use an alcohol based hand sanitizer.

Use your own drinking glass

Avoid sharing your drinking glasses and other utensils with others.

Be prepared when you travel away from home

Keep a waterless hand sanitizer handy for yourself and for your child while you are away from home.


Breast-fed babies develop natural resistance against infections.

No vaccine available

There is no vaccine for bronchiolitis yet. But a medication called palivizumab (Synagis) that can boost our immunity is recommended in some children. It can reduce the likelihood of RSV infections in infants with high risk of severe disease, as well as decrease the need for hospitalization and limit the severity of illness.

Palivizumab is usually given through a single injection into a large muscle, such as in the thigh, once in a month during the seasonal outbreaks — from November through March. However, as it is very expensive, its use is generally limited to infants at particularly high risk of RSV infection, such as pre-term infants or infants with a heart-lung condition or a compromised immune system.

7 Lifestyle and Coping

There are different ways to adapt your child's lifestyle in coping with bronchiolitis.

You can make your child more comfortable by relieving some of the symptoms, although it may not be possible to decrease the duration of your child's illness.

Here are some tips you can follow:

Humidify the air

Use a cool-mist humidifier or vaporizer to moisten the dry air in your child' s room. It helps to relieve congestion and cough. The humidifier should be cleaned regularly to prevent the growth of bacteria and molds.

Keep your child's room warm but not overheated as too much of heat can make the air dry. Another way to humidify the air is to run a hot shower in the bathroom and letting the steam fill up the room. Making your child sit in this room for about 15 minutes can help ease a fit of coughing.

Let your child stay upright

Being in an upright position help in breathing easily. Placing your infant in a car seat may help. If you want to leave your child in a car seat for a long time, such as for a nap, make sure that your child's head will not fall forwards, which can hinder proper breathing.

To do this, keep foam wedges or a rolled up blanket on either side of your child's head to hold it safely in place. Also check whether the seat has an appropriate slope, and this varies with your child's size and age.

Make sure your child drinks enough amount of clear fluids

In order to prevent dehydration, let your child drink plenty of clear fluids such as

  • water,
  • juice
  • gelatin water.

Your child may drink more slower than usual, because of congestion. Instill saline nasal drops to ease the congestion. To use them, put several drops into one nostril, then immediately bulb suction that nostril (but don't push the bulb too far in). Repeat the process in the other nostril. If your child is older, you may teach your child how to blow his or her nose.

Use OTC pain relievers

OTC pain relievers such as acetaminophen (Tylenol, others) may help relieve a sore throat and improve your child's ability to drink fluids. Do not give acetaminophen to children under 3 months of age, and never give your child aspirin. It is associated with a rare but serious illness called Reye's syndrome. OTC cold medications are not appropriate for bronchiolitis.

Keep your environment smoke-free

Smoke can aggravate the symptoms of respiratory infection. Avoid smoking cigarettes inside your house or car.

8 Risk and Complications

One of the greatest risk factors for the development of bronchiolitis is:

  • Age – being younger than 6 months old, because at this time, the infant's lungs and immune system are not fully developed.

Other factors that have been associated with an increased risk of bronchiolitis in infants, or more severe illness due to bronchiolitis, include:

  • Not being breast-fed — breast-fed babies receive immune benefits from the mother
  • Low birth weight in prematurely born infants
  • An underlying severe congenital heart or lung disease
  • A depressed immune system caused by congenital or acquired immune deficiency diseases
  • Airway anomaly
  • Exposure to tobacco smoke due to parental smoking
  • Contact with multiple number of children, such as in a day care facility
  • Crowded living environment
  • Having siblings who attend school or day care and bring home the infection

Complications of severe bronchiolitis may include 

  • Cyanosis, a condition which involves bluish discoloration of the skin, particularly of the lips. This is due to lack of oxygen.
  • Acute bronchiolitis in young infants can sometimes cause long pauses in breathing (apnea).
  • Dehydration

Fatigue and respiratory failure

If these complications occur, your child may need to stay at a hospital. In severe respiratory failure, a tube is inserted into the trachea to help the child's breathe easliy until the infection subsides.

Observe closely for the signs of bronchiolitis if your infant was born before term or has a heart or lung disorder or depressed immune system. Once the infection develops, it may turn serious rapidly as signs and symptoms of the underlying disorders become worse.

RSV can also cause pneumonia. Sometimes, a second infection, such as bacterial pneumonia may occur at the same time, but this is rare. Reinfections with RSV after the initial episode may occur but are not as severe.

9 Related Clinical Trials