Current Environment:


Recall Alert

There is a voluntary recall of Potassium Chloride Extended-Release Capsules. Learn more

What is bronchiolitis?

Bronchiolitis is an infection of the lower respiratory tract that usually affects infants. There is swelling in the bronchioles (smaller airways) of the lung, which causes an obstructed airflow.

Seventy-five percent of bronchiolitis occurs in the first year of a baby’s life. Bronchiolitis usually occurs in the winter and spring, and the condition is most common in babies between 2 to 6 months of age. Bronchiolitis is the leading cause of hospitalization among infants.

What risk factors are associated with bronchiolitis?

Risk factors that increase the likelihood that your child may develop bronchiolitis include:

  • Exposure to smoke
  • Day care attendance
  • Having older children in the home
  • Not having been breast-fed

Can bronchiolitis be prevented?

There is an injection that can help decrease your baby’s chance of getting RSV, the most common cause of bronchiolitis in children under 5 years of age. It is currently recommended only for high-risk infants, including premature infants (age at birth less than 35 weeks) and infants with chronic lung disease.

The medication is called either Palivizumab (Synagis), or respiratory syncytial immune globulin (RSV-IGIV). Your baby’s physician will be able to talk with you about whether this may be an option.

Bronchiolitis | Symptoms & Causes

What are the symptoms of bronchiolitis?

While each child may experience symptoms of bronchiolitis differently, your child might experience:

  • Common cold symptoms, including:
    • Runny nose
    • Congestion
    • Fever
    • Cough (this may become more severe as the condition progresses)
  • Changes in breathing patterns (your child may be breathing fast or hard and/or you may hear wheezing or a high-pitched sound)
  • Decreased appetite (your infant may not eat well)
  • Irritability
  • Vomiting

What causes bronchiolitis?

Bronchiolitis is most often caused by a virus, usually the respiratory syncytial virus (RSV). But many other viruses have been involved, including:

Some bacteria can also cause bronchiolitis, such as:

  • Mycoplasma pneumoniae
  • Chlamydia pneumoniae

Initially, the virus causes an infection in the upper respiratory tract, and then spreads downward into the lower tract. Here, the virus inflames or even kills cells inside the respiratory tract. This leads to obstructed airflow in and out of your child's lungs.

Bronchiolitis | Diagnosis & Treatments

How is bronchiolitis diagnosed?

Doctors usually diagnose bronchiolitis solely through physical examination and taking the history of your child, but they may order additional tests to rule out other diseases, such as pneumonia or asthma. To help the confirm the diagnosis, the doctor may also order:

  • Chest X-rays: a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
  • Blood tests
  • Pulse oximetry: an oximeter is a small machine that measures the amount of oxygen in the blood. To obtain this measurement, a small sensor (like a Band-Aid) is taped onto your child’s finger or toe. When the machine is on, a small red light can be seen in the sensor. The sensor is painless, and the red light does not get hot.
  • Nasopharyngeal swab: These tests quickly indicate the presence of RSV and other viruses.

How is bronchiolitis treated?

Most cases of bronchiolitis are mild and can be treated at home. Because there is no cure for the disease (antibiotics don't work against bronchiolitis), the goal of treatment is to lessen any discomfort your child may be feeling from the symptoms. If the physician feels your child is stable enough to be treated at home, she may recommend:

  • Increased fluid intake (giving your child more liquids)
  • Frequent suctioning (with a bulb syringe) of your child's nose and mouth (to help get rid of thick secretions)
  • Breathing treatments, as ordered by your child's doctor
  • Keeping your child's head elevated while sleeping
  • Medications (to help open your child's airways), as ordered by your child's doctor

If your infant is having severe breathing problems, he may be treated in the hospital. Here, treatment may include:

  • Intravenous (IV) fluids if your child is unable to drink well
  • Oxygen therapy
  • Frequent suctioning of your child's nose and mouth (to help get rid of thick secretions)
  • Breathing treatments, as ordered by your child's doctor

Your child's physician will determine the proper treatment plan, taking into consideration:

  • Your baby's gestational age, overall health, and medical history
  • Your baby's tolerance for specific medications, procedures, or therapies
  • Extent of the condition
  • Expectations for the course of the condition
  • Your opinion or preference

How we care for bronchiolitis

Here at Boston Children’s Hospital, we are actively working on research designed to target the identification of genes that underlie susceptibility to RSV bronchiolitis and subsequent.

Bronchiolitis | Programs & Services