RSV and Bronchiolitis
- Dr. Su
What is RSV?
RSV stands for respiratory syncytial virus and is a virus that causes respiratory tract illnesses in people of all ages during the fall and winter seasons. Nearly all children will have had RSV by the time they turn 2 and getting it once does not prevent one from getting it again in the future (although subsequent infections tend to be less severe). For most kids and adults, getting RSV simply leads to an upper respiratory infection (or the common cold). However, for infants and younger children typically under the age of 2, RSV can sometimes progress to lower respiratory tract infections, such as bronchiolitis and/or pneumonia, which can often have a more prolonged or severe course.
What is bronchiolitis?
The short answer: an infection of the bronchioles. This can be caused by RSV (which is the most common cause) but can also be caused by many other viruses. And what exactly are bronchioles? I oftentimes describe to parents (forgive me if you’ve already heard this spiel) that bronchioles are like branches to a tree. Imagine your respiratory tract as an upside-down tree. Your airway starting from your nose to your windpipe (or trachea) forms the trunk, then it branches out into the initial thick branches (bronchi), followed by the many small branches at the end (bronchioles). This is an over-simplification but having a basic understanding and visualization of what is infected can be helpful in understanding the symptoms that can arise from having bronchiolitis.
What are the symptoms of bronchiolitis?
Kids with bronchiolitis can have all the symptoms of the common cold (fever, cough, congestion, runny nose) in addition to having wheezing, fast breathing, and labored breathing (nostril flaring, belly breathing, tugging of the lower neck muscles, and tugging of the muscles in between the ribs). Symptoms tend to get worse around days 3 to 5 of illness followed by resolution around 1 to 2 weeks on average. While bronchiolitis is the leading cause of hospitalization in young infants, the vast majority of kids get better with routine supportive care at home (saline sprays, suctioning, humidifier, etc.).
When should I get concerned? When should I bring my child in? What kind of testing can be done?
You should seek medical attention if he/she is having any changes in their breathing patterns as listed above, high fever > 104 degrees, prolonged fever, symptoms progressively worsening beyond 5-7 days, and any concern for dehydration as kids with bronchiolitis tend to eat and drink poorly.
There is a test for RSV but we don’t routinely test for this in the clinic setting since it rarely changes our treatment plan for your child.
There are also currently no medications to treat RSV and antibiotics are not helpful unless there is a concurrent bacterial infection.
- Piedra, P., & Stark, A. (2019). Bronchiolitis in infants and children: Clinical features and diagnosis. In M.M. Torchia (Ed.), UpToDate. Retrieved January 30, 2020, from https://www.uptodate.com/contents/bronchiolitis-in-infants-and-children-clinical-features-and-diagnosis
- Barr, F., & Graham, B. (2019). Respiratory syncytial virus infection: Clinical features and diagnosis. In M.M. Torchia (Ed.), UpToDate. Retrieved January 30, 2020, from https://www.uptodate.com/contents/respiratory-syncytial-virus-infection-clinical-features-and-diagnosis