What is bronchiolitis?

Bronchiolitis is a common respiratory infection in young children that causes inflammation and congestion in the lungs' small breathing tubes (bronchioles). Not to be confused with bronchitis, which affects the larger, more central airways and is typically found in adults, bronchiolitis usually affects children under the age of 2 and is most common in infants 3 to 6 months. 

Symptoms of bronchiolitis (the most severe being difficulty breathing) can last up to 14 days and usually resolve without medical treatment. However, bronchiolitis in sick or premature infants or children with other chronic health problems can be serious enough to require hospitalization. Severe episodes of bronchiolitis have been associated with the development of asthma, although the link between the two illnesses is still unclear.

How do children get bronchiolitis?

Bronchiolitis occurs when a virus enters the respiratory system, makes its way into the bronchioles, and causes these small breathing tubes to swell. Infants can develop bronchiolitis after coming into contact with an adult or older child infected with the cold or flu virus. Though several viruses can lead to bronchiolitis, respiratory syncytial virus (RSV) is the most common cause. Since children with bronchiolitis can be a source of infection, their contact with others should be limited as much as possible until their symptoms subside. 

What are the symptoms of bronchiolitis?

Like many respiratory illnesses, early bronchiolitis symptoms resemble the common cold, such as runny nose, mild cough, and fever. After a day or two, symptoms can progress to labored breathing, or your child may make a whistling noise when he exhales (wheezing). Many children will also get an ear infection during this time. 

When should I call a doctor?

The American Academy of Pediatrics (AAP) recommends seeking prompt medical attention if your child has difficulty breathing or shows signs of dehydration. This is especially important if your child is younger than 12 weeks old or has other risk factors for bronchiolitis — including premature birth or a heart or lung condition.

Signs of breathing difficulties include:

  • Audible wheezing sounds
  •  Breathing very fast and shallowly
  •  Labored breathing
  •  Grunting and tightening stomach muscles when breathing
  •  Breathing too fast to eat or drink
  •  Skin turning blue, especially the lips and fingernails (cyanosis)

Signs of dehydration include:

  • Breastfeeding less or refusal to drink enough
  • Crying without tears
  • Urinating less
  • Dry mouth
  • Vomiting
  • Sinking in of the fontanelles (soft spots) 

Children with a weakened immune system are at the greatest risk for severe bronchiolitis. Parents should call their child’s doctor immediately if their child shows signs of bronchiolitis and has any of the following: cystic fibrosis, congenital heart disease, immune deficiency disease, organ or bone marrow transplant, or cancer requiring chemotherapy.

How is bronchiolitis treated?

Unlike bacterial infections, viral infections don’t respond to antibiotics. Aside from rest and drinking lots of fluid, the AAP suggests using saline nose drops and a nasal aspirator to clear mucus from your baby’s nose to help her breathe easier. Acetaminophen or ibuprofen can be used to relieve fever (your child’s healthcare provider can recommend the correct dose, which should be based on weight rather than age). Parents are cautioned not to give their children aspirin due to the risk of Reye’s syndrome—a serious and sometimes fatal disease.

For more severe cases of bronchiolitis, your child’s healthcare provider may prescribe medication such as adrenaline (epinephrine) to open your child’s breathing tubes. Some children must be hospitalized and given humidified oxygen to ease breathing and intravenous fluids to prevent or treat dehydration. In rare cases, babies may be placed on a respirator (breathing machine) until symptoms subside. In addition, some healthcare providers give children oral steroids (dexamethasone) to reduce swelling and ease breathing.

How can bronchiolitis be prevented?

The best way to keep your family virus-free is to adopt healthy habits: frequent handwashing, keeping your child away from individuals with a cold, and not sharing cups or utensils. Since RSV is the leading cause of bronchiolitis, parents should take a few minutes to review practices that reduce the risk of RSV.

Last updated December 5, 2021

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