Next to the common cold, ear infections are the most commonly
diagnosed childhood illness in the United States. More than 3 out
of 4 kids have had at least one ear infection by the time they
reach 3 years of age. To understand how ear infections develop,
let's review how the ear works.
A Close Look at the Ear
Think about how you can feel speakers vibrate as you listen to
your favorite CD in the car or how you feel your throat vibrate
when you speak. Sound, which is made up of invisible waves of
energy, causes these vibrations. Every time you hear a sound, the
various structures of the ear have to work together to make sure
the information gets to the brain.
The ear is responsible for hearing and balance and is made up of
three parts - the outer ear, middle ear, and inner ear. Hearing
begins when sound waves that travel through the air reach the outer
ear, or pinna, which is the part of the ear that's visible. The
sound waves then travel from the pinna through the ear canal to the
middle ear, which includes the eardrum (a thin layer of tissue) and
three tiny bones called ossicles. When the eardrum vibrates, the
ossicles amplify these vibrations and carry them to the inner
ear.
The inner ear translates the vibrations into electric signals
and sends them to the auditory nerve, which connects to the brain.
When these nerve impulses reach the brain, they're interpreted
as sound.
To function properly, the middle ear must be at the same
pressure as the outside world. This is taken care of by the
eustachian tube, a small passage that connects the middle ear to
the back of the throat behind the nose.
By letting air reach the middle ear, the eustachian tube
equalizes the air pressure in the middle ear to the outside air
pressure. (When your ears "pop" while yawning or
swallowing, the eustachian tubes are adjusting the air pressure in
your middle ears.) The eustachian tube also allows for drainage of
mucus from the middle ear into the throat.
Sometimes, the eustachian tube may malfunction. For example,
when someone has a cold or an
allergy
affecting the nasal passages, the eustachian tube may become
blocked by congestion in its lining or by mucus within the tube.
This blockage will allow fluid to build up within the normally
air-filled middle ear. Bacteria or viruses that have entered the
middle ear through the eustachian tube can also get trapped in this
way. These germs can breed in the trapped fluid, eventually leading
to an ear infection.
About Middle Ear Infections
Inflammation in the middle ear area is known as otitis media.
When referring to an ear infection, doctors most likely mean
"acute otitis media" rather than the common ear
infection called
swimmer's ear
, or otitis externa.
Acute otitis media is the presence of fluid, typically pus, in
the middle ear with symptoms of pain, redness of the eardrum, and
possible fever.
Other forms of otitis media are either more chronic (fluid is in
the middle ear for 6 or more weeks) or the fluid in the middle ear
is temporary and not necessarily infected (called otitis media with
effusion).
Doctors try to distinguish between the different forms of otitis
because this affects treatment options. Not all forms of otitis
need to be treated with antibiotics.
Causes
Kids develop ear infections more frequently in the first 2 to 4
years of life for several reasons:
- Their eustachian tubes are shorter and more horizontal than
those of adults, which allows bacteria and viruses to find their
way into the middle ear more easily. Their tubes are also
narrower and less stiff, which makes them more prone to
blockage.
- The adenoids, which are gland-like structures located in the
back of the upper throat near the eustachian tubes, are large in
children and can interfere with the opening of the eustachian
tubes.
A number of other factors can contribute to kids getting ear
infections, such as exposure to cigarette smoke, bottle-feeding,
and day-care attendance.
Ear infections also occur more commonly in boys than girls, in
kids whose families have a history of ear infections, and during
the winter season when upper respiratory tract infections or colds
are frequent.
Signs and Symptoms
The signs and symptoms of acute otitis media may range from very
mild to severe:
- The fluid in the middle ear may push on the eardrum, causing
ear pain. An older child may complain of an earache, but a
younger child may tug at the ear or simply act irritable and cry
more than usual.
- Lying down, chewing, and sucking can also cause painful
pressure changes in the middle ear, so a child may eat less than
normal or have trouble sleeping.
- If the pressure from the fluid buildup is high enough, it can
cause the eardrum to rupture, resulting in drainage of fluid from
the ear. This releases the pressure behind the eardrum, usually
bringing relief from the pain.
Fluid buildup in the middle ear also blocks sound, which can
lead to temporary
hearing difficulties
. A child may:
- not respond to soft sounds
- turn up the television or radio
- talk louder
- appear to be inattentive at school
Other symptoms of acute otitis media can include:
- fever
- nausea
- vomiting
- dizziness
However, otitis media with effusion often has no symptoms. In
some kids, the fluid that's in the middle ear may create a
sensation of ear fullness or "popping." As with acute
otitis media, the fluid behind the eardrum can block sound, so mild
temporary hearing loss can happen, but might not be obvious.
Ear infections are also frequently associated with upper
respiratory tract infections and, therefore, with their common
signs and symptoms, such as a runny or stuffy nose or a cough.
Contagiousness
Ear infections are
not contagious,
though the cold that may lead to one can be.
Duration
Middle ear infections often go away on their own within 2 or 3
days, even without any specific treatment. If your doctor decides
to prescribe antibiotics, a 10-day course is usually
recommended.
For kids 6 years of age and older with a mild to moderate
infection, a shortened course of antibiotics (5 to 7 days) may be
appropriate.
But even after antibiotic treatment for an episode of acute
otitis media, fluid may remain in the middle ear for up to several
months.
Diagnosis and Treatment
A child who might have an ear infection should visit a
doctor, who should be able to make a diagnosis by taking a medical
history and doing a physical exam.
To examine the ear, doctors use an otoscope, a small instrument
similar to a flashlight, through which they can see the
eardrum.
There's no single best approach for treating all middle ear
infections. In deciding how to manage your child's ear
infection, a doctor will consider many factors, including:
- the type and severity of the ear infection
- how often your child has ear infections
- how long this infection has lasted
- your child's age
- risk factors your child may have
- whether the infection affects your child's hearing
The fact that most ear infections can clear on their own has led
a number of physician associations to recommend a
"wait-and-see" approach, which involves giving the child
pain relief without antibiotics for a few days.
Another important reason to consider this type of approach are
the limitations of
antibiotics
, which:
- won't help an infection caused by a virus
- won't eliminate middle ear fluid
- may cause side effects
- typically do not relieve pain in the first 24 hours and have
only a minimal effect after that
Also, frequent use of antibiotics can lead to the development of
antibiotic-resistant bacteria, which can be much more difficult to
treat.
However, kids who get a lot of ear infections may be prescribed
daily antibiotics by their doctor to help prevent future
infections. And younger children or those with more severe illness
may require antibiotics right from the start.
The "wait-and-see" approach also might not apply to
children with other concerns, such as
cleft palate
, genetic conditions such as
Down syndrome
, underlying illnesses such as immune system disorders, or a
history of recurrent acute otitis media.
Kids with persistent otitis media with effusion (lasting longer
than 3 months) should be reexamined periodically (every 3 to 6
months) by their doctors. Often, though, even these kids won't
require treatment.
Whether or not the choice is made to treat with antibiotics, you
can help to reduce the discomfort of an ear infection by using
acetaminophen or ibuprofen for pain and fever as needed. Your
doctor may also recommend using pain-relieving eardrops as long as
the eardrum hasn't ruptured.
But certain children, such as those with persistent hearing loss
or
speech delay
, may require
ear tube surgery
. In some cases, an ear, nose, and throat doctor will suggest
surgically inserting tubes (called tympanostomy tubes) in the
tympanic membrane. This allows fluid to drain from the middle ear
and helps equalize the pressure in the ear because the eustachian
tube is unable to.
Prevention
Some factors associated with the development of ear infections
can't be changed (such as family history of frequent ear
infections), but certain lifestyle choices can minimize the risk
for kids:
-
breastfeed
infants for at least 6 months to help to prevent the development
of early episodes of ear infections. If a child is bottle-fed,
hold the infant at an angle rather than allowing the child to lie
down with the bottle.
- prevent exposure to secondhand smoke, which can increase the
frequency and severity of ear infections
- reduce exposure, if possible, to large groups of other kids,
such as in child-care centers. Because multiple upper respiratory
infections may also lead to frequent ear infections, limiting
exposure may result in less frequent colds early on and,
therefore, fewer ear infections.
- both parents and kids should practice good
hand washing
. This is one of the most important ways to decrease
person-to-person transmission of the
germs
that can cause colds and, therefore, ear infections.
- keep children's
immunizations
up-to-date, because certain vaccines can help prevent ear
infections
Also be aware that research has shown that cold and allergy
medications, such as antihistamines and decongestants, aren't
helpful in preventing ear infections.
When to Call the Doctor
Although quite rare, ear infections that don't go away or
severe repeated middle ear infections can lead to complications,
including spread of the infection to nearby bones. So
kids with an earache or a sense of fullness in the ear,
especially when combined with fever, should be evaluated by their
doctors if they aren't improving.
Other conditions can also result in earaches, such as
teething
, a foreign object in the ear, or hard earwax. Consult your doctor
to help determine the cause of the discomfort and how to treat
it.
Reviewed by:
Joel Klein, MD
Date reviewed: June 2008
Note: All information is for educational purposes only. For specific medical advice,
diagnoses, and treatment, consult your doctor.
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