Thursday, 24 December 2015

A Kids' Virus You Should Know About

It's that time of year again. No, not for last-minute Christmas shopping, but for a particularly nasty virus that in children can cause everything from mild common-cold symptoms to breathing problems bad enough to hospitalize a child - or, rarely, even death.

Respiratory syncytial virus, or RSV, is very common, with infections occurring in 90 percent of children before their second birthday. Fortunately, the majority of these infections cause relatively mild congestion and runny nose. But for about 20 to 30 percent of those younger than 2, the virus travels deep inside the lungs, resulting in bronchiolitis, a disease that causes the small airways (or bronchioles) in the lungs to fill up with thick mucus and dead cells from the lining of the airway. This makes the airways narrower, forcing the child to work harder to move air through a smaller tube - like breathing through a soda straw instead of a snorkel.

RSV is transmitted in the same way as many other respiratory viruses: by germs from a child's respiratory secretions being passed to another child either by coughing or sneezing, or through direct contact between people or with a contaminated surface. As you can imagine, it can spread pretty quickly in a room full of kids.

Most children with bronchiolitis can be diagnosed with just a physical exam. We doctors often hear the cough from outside the examination room and see the snotty nose when we enter. When we listen to the lungs, it sounds as if the airways are full of mucus - because they are. All the areas of the lungs sound about the same; that helps to rule out bacterial pneumonia, which is often localized in one spot. Wheezing - which doesn't always mean asthma - is common. And many children with RSV need to breathe harder or faster than normal.

Some doctors will order a chest X-ray or a test to look for the RSV virus, but that's usually not necessary. Chest X-rays that reveal bronchiolitis are sometimes difficult to distinguish from those that show pneumonia, and that can mean unnecessary treatment with antibiotics.
Once the diagnosis is made, the question is what to do about it. For the majority of kids, with relatively mild symptoms and without significant distress, the best treatment is symptomatic care. That means staying home, using saline drops and nasal suction for a small child (or tissues for an older one) to keep the nose clear, encouraging fluid intake to keep secretions thin and keeping an eye out for worsening symptoms.

Children with more-severe symptoms, such as rapid or labored breathing or decreased fluid intake, may need to be admitted to the hospital. But even there, the mainstays of treatment are sucking out the snot and keeping the kid hydrated. (Hospitals just have better tools for the job than most families do.)

Over the years, doctors have tried a lot of things to treat RSV. Steroids seemed to make sense (because we use them for asthma and croup), but they don't help with bronchiolitis. Inhaled albuterol or epinephrine doesn't usually help either, because bronchiolitis isn't an issue of constriction or swelling of the airways: It's just that they are full of mucus. There are a few kids out there - mostly those who already have a history of recurrent wheezing - who may benefit from albuterol, an inhaled medicine that relaxes muscles in the airways. But that benefit is usually pretty minimal.

In fact, if you read the American Academy of Pediatrics' guidelines for caring for children with bronchiolitis, it sounds like a list of things not to do. That's because there are very few interventions that actually help. Doctors can run IV fluids for dehydrated kids or try some saline in a nebulizer to help loosen up the mucus. And they can help kids breathe with some oxygen or higher-flow air - or in very severe cases, with a ventilator. And then it's just a matter of waiting until the child is healthy enough to go home.

The good news is that the symptoms tend to peak around Day 4 and then gradually resolve over the next few days. It might seem as if it lasts forever, but both parent and child will make it through.
Although most of cases of bronchiolitis can be safely managed at home, here are some things for parents to keep in mind:

- An infant younger than 2 months with a temperature of 100.4 degrees or higher requires medical evaluation. While the fever could certainly be caused by RSV or a similar virus, it's important to rule out other possible life-threatening causes for the fever.

- Any child who stops breathing, turns blue or gray, or doesn't respond to stimulation needs emergency.

- Children who are not able to drink enough fluids to stay hydrated should be evaluated for dehydration.

- Any child who is breathing harder or faster than usual or seems to have difficulty breathing should be seen by a doctor.

- In kids who seemed to be recovering, worsening symptoms or a new fever could indicate pneumonia, an ear infection or other complications and should be seen by a doctor.

- Other symptoms that concern you should be brought to the attention of your doctor.

If your child needs to be seen, try to get an appointment with the young patient's regular doctor. It's much easier to evaluate children at their worst when a doctor has seen them at their best. And if your child's doctor isn't available, try to find an urgent-care or emergency facility that sees children frequently or exclusively.

It would be great if RSV could be prevented. Unfortunately, there is no vaccine for it, although scientists are working to develop one. At this time, the best thing we have is a monthly injection of antibodies to RSV (called pavilizumab, or Synagis), which is intended to minimize the severity of an infection if it develops. This medication is very expensive (about $2,000 per dose, or $10,000 for the season). Because of the cost, it's reserved for those at the highest risk for complications: children who were extremely premature and infants with heart defects or chronic lung disease.

For the average healthy baby, breast-feeding and standard hygiene practices - such as hand washing and keeping your child away from sick people - are the best preventive medicine.