Ear infections are the most common reason parents bring their child to a doctor. Three out of four children will have at least one ear infection by their third birthday. Adults can also get ear infections, but they are less common.

The infection usually affects the middle ear and is called otitis media. The tubes inside the ears become clogged with fluid and mucus. This can affect hearing, because sound cannot get through all that fluid.

If your child isn't old enough to say "My ear hurts," here are a few things to look for

• Tugging at ears
• Crying more than usual
• Fluid draining from the ear
• Trouble sleeping
• Balance difficulties
• Hearing problems

Your health care provider will diagnose an ear infection by looking inside the ear with an instrument called an otoscope.

Often, ear infections go away on their own. Your health care provider may recommend pain relievers. Severe infections and infections in young babies may require antibiotics.

Children who get infections often may need surgery to place small tubes inside their ears. The tubes relieve pressure in the ears so that the child can hear again.

An ear infection is an inflammation of the middle ear, usually caused by bacteria, that occurs when fluid builds up behind the eardrum. Anyone can get an ear infection, but children get them more often than adults. Five out of six children will have at least one ear infection by their third birthday. In fact, ear infections are the most common reason parents bring their child to a doctor. The scientific name for an ear infection is otitis media (OM).

Our auditory system converts pressure waves into meaningful sounds. This translates into our ability to hear the sounds of nature, to appreciate the beauty of music, and to communicate with one another through spoken language. This section will provide an overview of the basic anatomy and function of the auditory system. It will include a discussion of how the sensory stimulus is translated into neural impulses, where in the brain that information is processed, how we perceive pitch, and how we know where sound is coming from.

Anatomy of the Auditory System

The ear can be separated into multiple sections. The outer ear includes the pinna, which is the visible part of the ear that protrudes from our heads, the auditory canal, and the tympanic membrane, or eardrum. The middle ear contains three tiny bones known as the ossicles, which are named the malleus (or hammer), incus (or anvil), and the stapes (or stirrup). The inner ear contains the semi-circular canals, which are involved in balance and movement (the vestibular sense), and the cochlea. The cochlea is a fluid-filled, snail-shaped structure that contains the sensory receptor cells (hair cells) of the auditory system (Figure).

The ear is divided into outer (pinna and tympanic membrane), middle (the three ossicles: malleus, incus, and stapes), and inner (cochlea and basilar membrane) divisions.

Sound waves travel along the auditory canal and strike the tympanic membrane, causing it to vibrate. This vibration results in movement of the three ossicles. As the ossicles move, the stapes presses into a thin membrane of the cochlea known as the oval window. As the stapes presses into the oval window, the fluid inside the cochlea begins to move, which in turn stimulates hair cells, which are auditory receptor cells of the inner ear embedded in the basilar membrane. The basilar membrane is a thin strip of tissue within the cochlea.

The activation of hair cells is a mechanical process: the stimulation of the hair cell ultimately leads to activation of the cell. As hair cells become activated, they generate neural impulses that travel along the auditory nerve to the brain. Auditory information is shuttled to the inferior colliculus, the medial geniculate nucleus of the thalamus, and finally to the auditory cortex in the temporal lobe of the brain for processing. Like the visual system, there is also evidence suggesting that information about auditory recognition and localization is processed in parallel streams (Rauschecker & Tian, 2000; Renier et al., 2009).

Is your child’s ear hurting? It could be an ear infection. Children are more likely than adults to get ear infections. Talk to your child’s doctor about the best treatment.

Some ear infections, such as middle ear infections, need antibiotic treatment, but many can get better without antibiotics.

What is an ear infection?

There are different types of ear infections. Middle ear infection (acute otitis media) is an infection in the middle ear.

Another condition that affects the middle ear is called otitis media with effusion. It occurs when fluid builds up in the middle ear without being infected and without causing fever, ear pain, or pus build-up in the middle ear.

When the outer ear canal is infected, the condition is called swimmer’s ear, which is different from a middle ear infection.

Causes

A middle ear infection may be caused by:

• Bacteria, like Streptococcus pneumoniae and Haemophilus influenzae (nontypeable)—the two most common bacterial causes
• Viruses, like those that cause colds or flu

See a doctor right away if your child is younger than 3 months old and has a fever of 100.4 °F (38 °C) or higher.

Symptoms

Common symptoms of middle ear infection in children can include:

• Ear pain
• Fever
• Fussiness or irritability
• Rubbing or tugging at an ear
• Difficulty sleeping

When to Seek Medical Care

See a doctor if your child has:

• A fever of 102.2°F (39°C) or higher
• Pus, discharge, or fluid coming from the ear
• Worsening symptoms
• Symptoms of a middle ear infection that last for more than 2–3 days
• Hearing loss

This list is not all-inclusive. Please see a doctor for any symptom that is severe or concerning.

Treatment

A doctor will determine what type of illness your child has by asking about symptoms and doing a physical examination. Your doctor can make the diagnosis of a middle ear infection by looking inside your child’s ear to examine the eardrum and see if there is pus in the middle ear.

Antibiotics are often not needed for middle ear infections because the body’s immune system can fight off the infection on its own. However, sometimes antibiotics, such as amoxicillin, are needed to treat severe cases right away or cases that last longer than 2–3 days.

For mild cases of middle ear infection, your doctor might recommend watchful waiting or delayed antibiotic prescribing.

• Watchful waiting: Your child’s doctor may suggest watching and waiting to see if your child needs antibiotics. This gives the immune system time to fight off the infection. If your child doesn’t feel better after 2–3 days of rest, extra fluids, and pain relievers, the doctor may write a prescription for an antibiotic.
• Delayed prescribing: Your child’s doctor may give an antibiotic prescription but suggest that you wait 2–3 days to see if your child is still sick before filling it.

How to Feel Better

Some ways to feel better—whether or not antibiotics are needed for an ear infection:

• Rest.
• Drink extra water or other fluids.
• Take acetaminophen or ibuprofen to relieve pain or fever. Ask your doctor or pharmacist about over-the-counter medicines that can help you feel better. Always use over-the-counter medicines as directed.

Over-the-Counter Medicine and Children

Be careful about giving over-the-counter medicines to children. Not all over-the-counter medicines are recommended for children of certain ages.

• Pain relievers:
  • Children younger than 6 months: only give acetaminophen.
  • Children 6 months or older: it is OK to give acetaminophen or ibuprofen.
  • Never give aspirin to children because it can cause Reye’s syndrome, a rare but very serious illness that harms the liver and brain.

• Cough and cold medicines:
  • Children younger than 4 years old: do not use unless a doctor specifically tells you to. Use of over-the-counter cough and cold medicines in young children can result in serious and potentially life-threatening side effects.
  • Children 4 years or older: discuss with your child’s doctor if over-the-counter cough and cold medicines are safe to give to your child for temporary symptom relief.

Be sure to ask your doctor or pharmacist about the right dosage of over-the-counter medicines for your child’s age and size. Also, tell your child’s doctor and pharmacist about all prescription and over-the-counter medicines they are taking.

Prevention

You can help prevent ear infections by doing your best to stay healthy and keep others healthy, including:

• Receive recommended vaccines, such as flu vaccine and pneumococcal vaccine. Pneumococcal vaccine protects against a common cause of middle ear infections, Streptococcus pneumonia.
• Clean your hands.

• Breastfeed exclusively until your baby is 6 months old and continue to breastfeed for at least 12 months.
• Don’t smoke and avoid exposure to secondhand smoke.
• Dry your ears thoroughly after swimming.

An ear infection usually is caused by bacteria and often begins after a child has a sore throat, cold, or other upper respiratory infection. If the upper respiratory infection is bacterial, these same bacteria may spread to the middle ear; if the upper respiratory infection is caused by a virus, such as a cold, bacteria may be drawn to the microbe-friendly environment and move into the middle ear as a secondary infection. Because of the infection, fluid builds up behind the eardrum.

The middle ear—which is where ear infections occur—is located between the eardrum and the inner ear. Within the middle ear are three tiny bones called the malleus, incus, and stapes that transmit sound vibrations from the eardrum to the inner ear. The bones of the middle ear are surrounded by air.

The inner ear contains the labyrinth, which help us keep our balance. The cochlea, a part of the labyrinth, is a snail-shaped organ that converts sound vibrations from the middle ear into electrical signals. The auditory nerve carries these signals from the cochlea to the brain.

Other nearby parts of the ear also can be involved in ear infections. The eustachian tube is a small passageway that connects the upper part of the throat to the middle ear. Its job is to supply fresh air to the middle ear, drain fluid, and keep air pressure at a steady level between the nose and the ear.

Adenoids are small pads of tissue located behind the back of the nose, above the throat, and near the eustachian tubes. Adenoids are mostly made up of immune system cells. They fight off infection by trapping bacteria that enter through the mouth.

There are several reasons why children are more likely than adults to get ear infections.

Eustachian tubes are smaller and more level in children than they are in adults. This makes it difficult for fluid to drain out of the ear, even under normal conditions. If the eustachian tubes are swollen or blocked with mucus due to a cold or other respiratory illness, fluid may not be able to drain.

A child’s immune system isn’t as effective as an adult’s because it’s still developing. This makes it harder for children to fight infections.

As part of the immune system, the adenoids respond to bacteria passing through the nose and mouth. Sometimes bacteria get trapped in the adenoids, causing a chronic infection that can then pass on to the eustachian tubes and the middle ear.

There are three main types of ear infections. Each has a different combination of symptoms.

• Acute otitis media (AOM) is the most common ear infection. Parts of the middle ear are infected and swollen and fluid is trapped behind the eardrum. This causes pain in the ear—commonly called an earache. Your child might also have a fever.
• Otitis media with effusion (OME) sometimes happens after an ear infection has run its course and fluid stays trapped behind the eardrum. A child with OME may have no symptoms, but a doctor will be able to see the fluid behind the eardrum with a special instrument.
• Chronic otitis media with effusion (COME) happens when fluid remains in the middle ear for a long time or returns over and over again, even though there is no infection. COME makes it harder for children to fight new infections and also can affect their hearing.

Being up all night with a child crying from the pain of an ear infection can be a nightmare. But it’s not uncommon. Most children in developed countries get at least one ear infection by the age of five.

Most ear infections happen in the middle ear, the part of the ear behind the eardrum. The middle ear is connected to the upper part of the throat by the eustachian tube. It normally lets fresh air into your middle ear and lets fluid drain out.

After a cold or other infection, the virus or bacteria that caused the illness can spread to the middle ear. When this happens, the eustachian tube can swell up or become blocked with mucus. This can trap the germs and cause an ear infection. The trapped germs can cause more swelling and fluid buildup. That’s what causes the pain of an ear infection.

Why do so many young children get ear infections? “In younger kids, the eustachian tube, as well as the immune system, are still developing. Some kids might also have an underactive immune system that can’t fight the infection,” explains Dr. Michael Hoa, an ear, nose, and throat specialist and researcher at NIH.

In older children and adults, the eustachian tube is large and slanted to drain fluid from the middle ear. In younger children, this tube is narrower and more level, so it’s more likely to get blocked.

If the pain won’t go away or your child has fluid coming out of their ear, you should visit a doctor. Ear infections can also make a child fussy, cause a fever, or create trouble hearing.

Many ear infections don’t need to be treated. They often clear up on their own.

“There is a huge push not to overprescribe antibiotics,” Hoa says. Bacteria can become resistant to the effects of these drugs. So doctors try not to give them, except for severe cases.

When drugs are necessary, it’s important that they be taken for the full time your doctor tells you. But it’s not always easy to get young children to take medications.

A recent NIH-funded study tested whether antibiotics could be taken for less than the standard 10–day treatment. Unfortunately, the shortened treatment didn’t work as well and had no benefits.

NIH-funded researchers are now looking for better ways to treat an ear infection. One group is testing injectable gels to deliver medication right into the ear canal.

One major cause of ear infections is a type of bacteria called Haemophilus influenzae, or H. influenzae. These bacteria can cluster together to make a biofilm, a thin, slimy coating that your body has a hard time getting rid of. Even antibiotics can be ineffective against them. Ear infections that keep coming back often involve biofilms.

A vaccine introduced in 1987 already prevents ear infections caused by one strain of H. influenzae. Researchers are working on developing vaccines to protect against other strains. They’re also looking at what specific nutrients H. influenzae needs to grow the biofilms. Restricting those nutrients may be a new way to fight these bacteria.

If your child has repeated ear infections or trouble hearing, your doctor may suggest draining your child’s ear with small tubes to help maintain a healthy environment.

Ear infections aren’t contagious. But there are things you can do to lower your chances of getting one. See the Wise Choices box for tips on preventing ear infections.

Ways to Help Prevent Ear Infections

• Stay up to date on vaccinations, including an annual flu shot.
• Wash your hands often.
• Avoid close contact with people who have a cold or other illness.
• Avoid secondhand smoke.
• Never let your baby sleep with a bottle. The liquid may accidentaly enter the ear.

Most ear infections happen to children before they’ve learned how to talk. If your child isn’t old enough to say “My ear hurts,” here are a few things to look for:

• Tugging or pulling at the ear(s)
• Fussiness and crying
• Trouble sleeping
• Fever (especially in infants and younger children)
• Fluid draining from the ear
• Clumsiness or problems with balance
• Trouble hearing or responding to quiet sounds

The first thing a doctor will do is ask you about your child’s health. Has your child had a head cold or sore throat recently? Is he having trouble sleeping? Is she pulling at her ears? If an ear infection seems likely, the simplest way for a doctor to tell is to use a lighted instrument, called an otoscope, to look at the eardrum. A red, bulging eardrum indicates an infection.

A doctor also may use a pneumatic otoscope, which blows a puff of air into the ear canal, to check for fluid behind the eardrum. A normal eardrum will move back and forth more easily than an eardrum with fluid behind it.

Tympanometry, which uses sound tones and air pressure, is a diagnostic test a doctor might use if the diagnosis still isn’t clear. A tympanometer is a small, soft plug that contains a tiny microphone and speaker as well as a device that varies air pressure in the ear. It measures how flexible the eardrum is at different pressures.

Many doctors will prescribe an antibiotic, such as amoxicillin, to be taken over seven to 10 days. Your doctor also may recommend over-the-counter pain relievers such as acetaminophen or ibuprofen, or eardrops, to help with fever and pain. (Because aspirin is considered a major preventable risk factor for Reye’s syndrome, a child who has a fever or other flu-like symptoms should not be given aspirin unless instructed to by your doctor.)

If your doctor isn’t able to make a definite diagnosis of OM and your child doesn’t have severe ear pain or a fever, your doctor might ask you to wait a day or two to see if the earache goes away. The American Academy of Pediatrics issued guidelines in 2013 that encourage doctors to observe and closely follow these children with ear infections that can’t be definitively diagnosed, especially those between the ages of 6 months to 2 years. If there’s no improvement within 48 to 72 hours from when symptoms began, the guidelines recommend doctors start antibiotic therapy. Sometimes ear pain isn’t caused by infection, and some ear infections may get better without antibiotics. Using antibiotics cautiously and with good reason helps prevent the development of bacteria that become resistant to antibiotics.

If your doctor prescribes an antibiotic, it’s important to make sure your child takes it exactly as prescribed and for the full amount of time. Even though your child may seem better in a few days, the infection still hasn’t completely cleared from the ear. Stopping the medicine too soon could allow the infection to come back. It’s also important to return for your child’s follow-up visit, so that the doctor can check if the infection is gone.

Middle ear infections are common in kids. The illness is often caused by bacteria, and can be treated with antibiotics. But bacteria can become resistant to antibiotics. That’s why it’s important to take these medications as directed.

Scientists have wondered if shorter treatments might reduce the risk of bacteria becoming resistant to antibiotics. Shorter treatments might also reduce other side effects. A new NIH-funded study provides some answers—at least for children under age 2.

The study enrolled 520 children, ages 6 to 23 months, who had middle-ear infections diagnosed using stringent criteria. Kids were randomly assigned to receive either a standard 10-day course of antibiotics or a shorter (5-day) treatment.

The scientists found that 77 of the 229 children (34%) in the 5-day treat­ment group did not improve or had worsening symptoms and signs of in­fection, compared to 39 of 238 (16%) who received the 10-day treatment.

After treatment, the researchers examined bacteria from the kids’ noses and throats. They’d expected the shorter treatment to reduce the development of drug-resistant bacteria. However, they found no significant differences between the 2 groups. Both treatment groups also had similar levels of side effects.

“The results of this study clearly show that for treating ear infections in children between 6 and 23 months of age, a 5-day course of antibiotic offers no benefit in terms of adverse events or antibiotic resistance,” says study lead Dr. Alejandro Hoberman of the University of Pittsburgh School of Medicine. The findings confirm that standard antibiotics prescribed for an ear infection should be taken the full 10 days in young children.

Your child should start feeling better within a few days after visiting the doctor. If it’s been several days and your child still seems sick, call your doctor. Your child might need a different antibiotic. Once the infection clears, fluid may still remain in the middle ear but usually disappears within three to six weeks.

Sometimes, fluid may stay in the middle ear for several weeks after the infection has cleared. This may cause temporary hearing loss. Usually, the fluid drains on its own and hearing improves without additional medical treatment. Sometimes, the fluid can become reinfected. If this happens, your child may need to take antibiotics again.

If fluid stays in the middle ear for more than several months, then hearing loss may result. In children younger than three years of age, the fluid can lead to speech and language delay. Sometimes it may be necessary to insert a tube through the ear drum and into the middle ear to drain the fluid. This operation is usually done by an otolaryngologist (ear, nose and throat surgeon). This operation is short in duration and children usually don’t have to stay in the hospital overnight.

If your child is taking antibiotics for an ear infection, call your doctor if your child:

• still has an earache, even after two to three days of treatment;

• has a fever over 39°C (102°F), or a fever that lasts more than three days;

• is very sleepy;

• is still fussy or cranky;

• is breathing quickly or has trouble breathing; and

• isn’t hearing well.

Currently, the best way to prevent ear infections is to reduce the risk factors associated with them. Here are some things you might want to do to lower your child’s risk for ear infections.

• Vaccinate your child against the flu. Make sure your child gets the influenza, or flu, vaccine every year.
• It is recommended that you vaccinate your child with the 13-valent pneumococcal conjugate vaccine (PCV13). The PCV13 protects against more types of infection-causing bacteria than the previous vaccine, the PCV7. If your child already has begun PCV7 vaccination, consult your physician about how to transition to PCV13. The Centers for Disease Control and Prevention (CDC) recommends that children under age 2 be vaccinated, starting at 2 months of age. Studies have shown that vaccinated children get far fewer ear infections than children who aren’t vaccinated. The vaccine is strongly recommended for children in daycare.
• Wash hands frequently. Washing hands prevents the spread of germs and can help keep your child from catching a cold or the flu.
• Avoid exposing your baby to cigarette smoke. Studies have shown that babies who are around smokers have more ear infections.
• Never put your baby down for a nap, or for the night, with a bottle.
• Don’t allow sick children to spend time together. As much as possible, limit your child’s exposure to other children when your child or your child’s playmates are sick.

To keep a middle ear infection from coming back, it helps to limit some of the factors that might put your child at risk, such as not being around people who smoke and not going to bed with a bottle. In spite of these precautions, some children may continue to have middle ear infections, sometimes as many as five or six a year. Your doctor may want to wait for several months to see if things get better on their own but, if the infections keep coming back and antibiotics aren’t helping, many doctors will recommend a surgical procedure that places a small ventilation tube in the eardrum to improve air flow and prevent fluid backup in the middle ear. The most commonly used tubes stay in place for six to nine months and require follow-up visits until they fall out.

If placement of the tubes still doesn’t prevent infections, a doctor may consider removing the adenoids to prevent infection from spreading to the eustachian tubes.

Researchers sponsored by the National Institute on Deafness and Other Communication Disorders (NIDCD) are exploring many areas to improve the prevention, diagnosis, and treatment of middle ear infections. For example, finding better ways to predict which children are at higher risk of developing an ear infection could lead to successful prevention tactics.

Another area that needs exploration is why some children have more ear infections than others. For example, Native American and Hispanic children have more infections than do children in other ethnic groups. What kinds of preventive measures could be taken to lower the risks?

Doctors also are beginning to learn more about what happens in the ears of children who have recurring ear infections. They have identified colonies of antibiotic-resistant bacteria, called biofilms, that are present in the middle ears of most children with chronic ear infections. Understanding how to attack and kill these biofilms would be one way to successfully treat chronic ear infections and avoid surgery.

Understanding the impact that ear infections have on a child’s speech and language development is another important area of study. Creating more accurate methods to diagnose middle ear infections would help doctors prescribe more targeted treatments. Researchers also are evaluating drugs currently being used to treat ear infections, and developing new, more effective and easier ways to administer medicines.

NIDCD-supported investigators continue to explore vaccines against some of the most common bacteria and viruses that cause middle ear infections, such as nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis. One team is conducting studies on a method for delivering a possible vaccine without a needle.