What is Bronchiolitis?
Bronchiolitis is a common illness of the
respiratory tract
caused by an infection that affects the tiny airways, called the
bronchioles, that lead to the lungs. As these airways become
inflamed, they swell and fill with mucus, making breathing
difficult.
Bronchiolitis:
- most often affects infants and young children because their
small airways can become blocked more easily than those of older
kids or adults
- typically occurs during the first 2 years of life, with peak
occurrence at about 3 to 6 months of age
- is more common in males, children who have not been
breastfed, and those who live in crowded conditions
Day-care attendance and exposure to cigarette smoke also can
increase the likelihood that an infant will develop
bronchiolitis.
Although it's often a mild illness, some infants are at risk
for a more severe disease that requires hospitalization. Conditions
that increase the risk of severe bronchiolitis include prematurity,
prior chronic heart or lung disease, and a weakened immune system
due to illness or medications.
Kids who have had bronchiolitis may be more likely to develop
asthma
later in life, but it's unclear whether the illness causes
or triggers asthma, or whether children who eventually develop
asthma were simply more prone to developing bronchiolitis as
infants. Studies are being done to clarify the relationship between
bronchiolitis and the later development of asthma.
Bronchiolitis is usually caused by a viral infection, most
commonly
respiratory syncytial virus (RSV)
. RSV infections are responsible for more than half of all cases of
bronchiolitis and are most widespread in the winter and early
spring. Other viruses associated with bronchiolitis include
rhinovirus,
influenza (flu)
, and human metapneumovirus.
Signs and Symptoms
The first symptoms of bronchiolitis are usually the same as
those of a
common cold
:
- stuffiness
- runny nose
- mild cough
- mild fever
These symptoms last a day or two and are followed by worsening
of the cough and the appearance of wheezes (high-pitched whistling
noises when exhaling).
Sometimes more severe respiratory difficulties gradually
develop, marked by:
- rapid, shallow breathing
- a rapid heartbeat
- drawing in of the neck and chest with each breath, known as
retractions
- flaring of the nostrils
- irritability, with difficulty sleeping and signs of fatigue
or lethargy
The child may also have a poor appetite and may vomit after
coughing. Less commonly, babies, especially those born prematurely,
may have episodes where they briefly stop breathing (this is called
apnea) before developing other symptoms.
In severe cases, symptoms may worsen quickly. A child with
severe bronchiolitis may tire from the work of breathing and have
poor air movement in and out of the lungs due to the clogging of
the small airways. The skin can turn blue (called cyanosis), which
is especially noticeable in the lips and fingernails. The child
also can become
dehydrated
from working harder to breathe, vomiting, and taking in less during
feedings.
Contagiousness
The infections that cause bronchiolitis are contagious. The
germs can spread in tiny drops of fluid from an infected
person's nose and mouth, which may become airborne
via sneezes, coughs, or laughs, and also can end up on things
the person has touched, such as used tissues or toys.
Infants in child-care centers have a higher risk of contracting
an infection that may lead to bronchiolitis because they're in
close contact with lots of other young children.
Prevention
The best way to prevent the spread of viruses that can cause
bronchiolitis is frequent
hand washing
. It may help to keep infants away from others who have colds or
coughs. Babies who are exposed to cigarette smoke are more likely
to develop more severe bronchiolitis compared with those from
smoke-free homes. Therefore, it's important to avoid exposing
children to cigarette smoke.
Although a vaccine for bronchiolitis has not yet been developed,
a medication can be given to lessen the severity of the disease. It
contains antibodies to RSV and is injected monthly during peak RSV
season. The medication is recommended only for infants at high risk
of severe disease, such as those born very prematurely or those
with chronic lung disease.
Incubation
The incubation period (the time between infection and the onset
of symptoms) ranges from several days to a week, depending on the
infection causing the bronchiolitis.
Duration
Cases of bronchiolitis typically last about 12 days, but kids
with severe cases can cough for weeks. The illness generally peaks
on about the second to third day after the child starts coughing
and having difficulty breathing and then gradually resolves.
Professional Treatment
Fortunately, most cases of bronchiolitis are mild and require no
specific professional treatment. Antibiotics aren't useful
because bronchiolitis is caused by a viral infection, and
antibiotics are only effective against bacterial infections.
Medication may sometimes be given to help open a child's
airways.
Infants who have trouble breathing, are dehydrated, or appear
fatigued should always be evaluated by a doctor. Those who are
moderately or severely ill may need to be hospitalized, watched
closely, and given fluids and humidified oxygen. Rarely, in very
severe cases, some babies are placed on respirators to help them
breathe until they start to get better.
Home Treatment
The best treatment for most kids is time to recover and plenty
of fluids. Making sure a child drinks enough fluids can be a tricky
task, however, because infants with bronchiolitis may not feel like
drinking. They should be offered fluids in small amounts at more
frequent intervals than usual.
Indoor air, especially during winter, can dry out airways
and make the mucus stickier. Some parents use a cool-mist vaporizer
or humidifier in the child's room to help loosen mucus in the
airway and relieve cough and congestion. If you use one, clean it
daily with household bleach to prevent mold from building
up. Avoid hot-water and steam humidifiers, which can be
hazardous and can cause scalding.
To clear nasal congestion, try a bulb syringe and saline
(saltwater) nose drops. This can be especially helpful just before
feeding and sleeping. Sometimes, keeping the child in a slight
upright position may help improve labored breathing. Give
acetaminophen to reduce fever and make the child more
comfortable.
When to Call the Doctor
Call your doctor if your child:
- is breathing quickly, especially if this is accompanied by
retractions or wheezing
- might be dehydrated due to poor appetite or vomiting
- is sleepier than usual
- has a high fever
- has a worsening cough
- appears fatigued or lethargic
Seek immediate help if you feel your child is having difficulty
breathing and the cough, retractions, or wheezing are getting
worse, or if his or her lips or fingernails appear blue.
Reviewed by:
Yamini Durani, MD
Date reviewed: May 2007
Originally reviewed by:
Elana Pearl Ben-Joseph, MD
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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