Cause
An inflammation of the bronchioles, the lung’s smallest air passages, bronchiolitis is usually caused by a viral infection. The most common cause, especially during cold-weather epidemics, is respiratory syncytial virus (RSV). Other causes include mycoplasma, parainfluenza virus, influenza virus, and some adenoviruses.
Symptoms
Initial symptoms include congestion, runny nose, and mild cough for a day or two. These symptoms are followed by gradually increasing difficulty in breathing characterized by wheezing; rapid, shallow breathing (60 to 80 times a minute); rapid heartbeat; the sucking in of the skin over the neck and chest with each breath; and a cough. Fever may occur. Usually no vomiting or diarrhea occurs, although bouts of coughing may lead to vomiting.
How It Spreads
Respiratory syncytial virus and other viruses spread easily through families, child-care centers, and schools, especially in winter. Children contract the viruses by coming in contact with the nose and throat secretions of others.
Incubation Period
The incubation period is several days to a week, depending on the virus causing the infection.
How Long Symptoms Last
Most cases last about a week, but in severe cases, coughing may continue for a few weeks even after the child appears otherwise well.
When to Call Your Child’s Doctor
If your child is having trouble breathing, contact your child’s doctor immediately.
How the Diagnosis Is Made
The doctor will listen to the child’s lungs with a stethoscope and observe breathing. Rapid test for RSV is available to make the diagnosis.
Treatment
Most cases are mild and can be treated at home. Cases in very young infants or those with other medical problems such as prematurity, lung disease, or heart disease may require hospitalization for oxygen, intravenous fluids, other treatment, and monitoring. Antibiotics are not helpful unless there is a secondary infection caused by bacteria.
Home Treatment
Use a cool-mist humidifier during the dry winter months to keep air humid. (Clean every day to keep mold from growing.) Make sure your child gets enough fluids.
Prevention
Try to get your child to wash her hands frequently and avoid contact with sick children. Bronchiolitis occurs more commonly in male infants three to six months of age who have not been breastfed. Infants exposed to cigarette smoke are more likely to develop respiratory infections and have more severe symptoms. Some children become so ill from RSV infection that they need to be hospitalized, especially premature infants and those with lung or heart conditions. Synagis (palivizumab), a medication containing antibodies against RSV, is available to help prevent infection in these children. The drug is given as monthly injections during RSV season.
Contagious Periods
Most infants infected with RSV can continue to spread the virus for 5 to 12 days after the start of symptoms. Bronchiolitis, especially from RSV, is spread very easily because the virus remains alive in nasal secretions and saliva outside the body for hours. Someone sneezing very close to someone else or touching a surface contaminated with secretions could therefore give someone RSV fairly easily. Therefore, good hand washing is extremely important to prevent outbreaks and rapid spread through child-care centers, schools, and hospitals.
Complications
Complications from bronchiolitis include ear infections, and less commonly, secondary bacterial pneumonia. Sometimes, children with preexisting heart or lung conditions or who are born prematurely need hospitalization for oxygen or respiratory therapy. Up to 30 percent of children who develop bronchiolitis go on to develop some form of asthma, especially if there is a family history of asthma.