Bronchiolitis is one of the most common illnesses children, especially under age two, can get. For parents of younger children, it can be quite scary, but the overwhelming majority of children recover relatively quickly and without complications.
What is bronchiolitis?
Bronchiolitis is an infection in the part of the lungs called the bronchioles. The most common cause of bronchiolitis is RSV or the Respiratory Syncytial Virus. Other causes include Rhinovirus, Human Metapneumovirus, and the Influenza virus.
What happens in bronchiolitis?
In bronchiolitis the lining of the bronchioles sluffs off and clogs up the airways. While not a problem for older children, in younger infants such as those under three months of age, it can cause significant issues with breathing. Their airways are much smaller, and it doesn’t take much debris in the bronchiole tubes to cause problems. The coughing associated with bronchiolitis is the body’s way of trying to clear up the lungs, and the wheezing comes from all the gunk in the bronchiole tubes.
How is RSV spread?
RSV like all respiratory viruses is spread through the air by respiratory droplets. One sneeze can release millions of viruses into the air. The infected nasal secretions and respiratory droplets can live for up to 6 hours on hard surfaces making it easy for the virus to be spread through toys and counters.
Symptoms of bronchiolitis:
The first symptoms of bronchiolitis look just like the common cold. Runny nose, nasal congestion, low-grade fever, and cough. The degree of respiratory issues depends on the age of the child. Children under the age of 2 typically progress over the next few days with worsening cough and wheezing. Usually, the 4th day after symptoms start is the worse day if the cause of bronchiolitis is due to RSV. Infants, especially those under four months of age, and older infants and children with chronic lung diseases like asthma, can develop tachypnea (rapid breathing), retractions (pulling the ribs in on inspiration), grunting, get cyanotic (turn blue), or develop apnea (stop breathing). Any of these symptoms require prompt medical attention either in a physician’s office or in the ER.
How is it diagnosed?
Bronchiolitis is diagnosed by history and physical exam findings alone. The RSV virus can be found with a nose swab via PCR or viral culture. PCR stands for a polymerase chain reaction. A PCR machine takes the nasal secretions and sees if there is anything that matches what a known RSV virus looks like via DNA. If there is a match, it flags the sample as positive for RSV. You can also perform a viral culture, but that test can take several days and isn’t practical in the real world. PCR can also find other viruses and bacteria.
Treatment of Bronchiolitis:
Unfortunately, there aren’t any treatments for bronchiolitis. I know some that are reading this are quite puzzled. What about albuterol and steroids? The reason why albuterol doesn’t work is that it is a “bronchodilator.” The lung problems associated with bronchiolitis aren’t due to the airways spasming like in an asthma attack. It is just full of “gunk,” which albuterol can’t help clear. It's also the reason why steroids don’t work. Why are they written often then? While I can’t speak for any other physicians, I will often prescribe albuterol on the off chance that it may help. However, I won’t write for steroids as its completely unnecessary. Antibiotics are also inappropriate as the illness is due to a virus, not bacteria. Symptomatic care includes nasal suctioning, giving fever reducers as needed, making sure they stay hydrated, and rest.
Those that are hospitalized are often treated with supplemental oxygen if their levels are low or if severe enough, they may need to be put on a ventilator. As for what other treatments are given in the hospital setting this can vary so I won’t be discussing it here.
How long with the symptoms last?
Symptoms usually last about 7-10 days. The cough associated with bronchiolitis can last up to 3 weeks. Those infected can also be contagious for a few days after recovery. As a lot of my parents have heard me say, lack of fever has absolutely nothing to do with whether they are contagious or not.
How to prevent bronchiolitis:
There is nothing special when it comes to decreasing the risk of a child developing bronchiolitis. Good hand hygiene and cleaning hard surfaces like toys and countertops are excellent ways of reducing the risk of spreading viruses associated with bronchiolitis. You could also avoid daycares during the winter months, but that’s not practical for many working parents. The viruses associated with bronchiolitis and especially RSV are very contagious, and as many parents have heard me say, eventually, every child will get it. It’s just a matter of timing. Parental smoking is also a considerable risk factor. Second-hand cigarette smoke irritates the lining of a child’s airway, making it so much easier for viruses to infect them. It also keeps them sicker longer.
I do need to mention Synagis. Synagis is a preventative treatment given to a select group of children. Synagis is an injection of antibodies against RSV that given in 5 once-monthly doses. Prophylactic treatment is often limited to premature infants who were born before 29 weeks, babies who are born with heart defects, or babies with chronic lung disease who were born before 32 weeks. Children who qualify for Synagis are at a higher risk of severe problems such as the need to be on a ventilator or death. Synagis is typically given the first year of life although in special cases it may get approved for a second year. Synagis is very expensive costing between $7,500 to $15,000 for a full 5 dose course.
Studies have shown that there is a slightly increased risk of a child developing asthma if they develop bronchiolitis before six months of age.