Ear infections are also known as glue ear, secretory otitis media, middle ear infection, or serous otitis media.
Infections in the ear are well understood, and their common occurrence means that research is frequently carried out. This article explains the symptoms and causes of ear infections, the treatment options available, as well as the different types and testing methods.
Here are some key points about ear infections. More detail and supporting information is available in the main article.
- Ear infections are more common in young boys than young girls.
- Most ear infections improve without treatment.
- Vaccinating a child against the flu can help prevent ear infections.
- Biofilms of antibiotic-resistant bacteria may be to blame for prolonged and repeated cases of ear infection
- Secondhand smoke increases the risk of ear infections.
What is an ear infection?
Ear infections are very common and affect 5 out of 6 children in their first 3 years.
An ear infection is a bacterial or viral infection of the middle ear. This infection causes inflammation and the buildup of fluid within the internal spaces of the ear.
The middle ear is a air-filled space situated behind the eardrum. It contains vibrating bones that convert sound from outside of the ear into meaningful signals for the brain.
Ear infections are painful because the inflammation and buildup of excess fluid increases pressure on the eardrum.
An ear infection can be acute or chronic. Chronic ear infections may permanently damage the middle ear.
In adults, the symptoms are simple. Adults with ear infections experience ear pain and pressure, fluid in the ear, and reduced hearing. Children experience a wider range of signs. These include:
- tugging or pulling at the ear
- ear pain, especially when lying down
- difficulty sleeping
- crying more than normal
- loss of balance
- difficulty hearing
- lack of appetite
Ear infections are generally divided into three categories.
Acute otitis media (AOM)
AOM is the most common and least serious form of ear infection. The middle ear becomes infected and swollen, and fluid is trapped behind the eardrum. Fever can also occur.
Otitis media with effusion (OME)
After an ear infection has run its course, there may be some fluid left behind the eardrum. A person with OME may not experience symptoms, but a doctor will be able to spot the remaining fluid.
Chronic otitis media with effusion (COME)
COME refers to fluid repeatedly returning to the middle ear, with or without an infection present. This leads to a reduced ability to fight other infections and has a negative impact on hearing ability.
An ear infection often begins with a cold, flu, or allergic response. These increase mucus in the sinuses, and lead to the slow clearance of fluid by the eustachian tubes. The initial illness will also inflame the nasal passages, throat, and eustachian tubes.
The role of eustachian tubes
The eustachian tubes connect the middle ear to the back of the throat. The ends of these tubes open and close to regulate air pressure in the middle ear, resupply air to this area, and drain normal secretions.
A respiratory infection or allergy can block the eustachian tubes, causing a buildup of fluids in the middle ear. Infection can occur if this fluid becomes infected bacterially.
The eustachian tubes of young children are smaller and more horizontal than in older children and adults. This means that fluid is more likely to collect in the tubes rather than drain away, increasing the risk of an ear infection.
The role of adenoids
The adenoids are pads of tissue located at the back of the nasal cavity. They react to passing bacteria and viruses and play a part in immune system activity. The adenoids can sometimes trap bacteria, however. This can lead to infection and inflammation of the eustachian tubes and middle ear.
The adenoids are close to the openings of the eustachian tubes, and if they swell, they can cause the tubes to close. Children have relatively large adenoids that are more active than those of adults. These make children more likely to contract ear infections.
Tests and diagnosis
There are a number of ways to diagnose ear infections. Doctors will typically use a device called an otoscope.
Testing for ear infection is a relatively simple procedure and a diagnosis can often be made based on symptoms alone.
The doctor will generally use an otoscope, an instrument with a light attachment, to check for fluid behind the eardrum.
A physician will sometimes use a pneumatic otoscope to test for infection. This device checks for trapped fluid by releasing a puff of air into the ear. Any fluid behind the eardrum will cause the eardrum to move less than normal.
If in doubt, the doctor may use other methods to confirm a middle ear infection.
The doctor uses a device that seals off and adjusts the pressure inside the ear canal. The device measures the movement of the eardrum. This allows the physician to determine the pressure of the middle ear.
This method works by bouncing sound against the eardrum. The amount of sound that is bounced back indicates fluid buildup levels. A healthy ear will absorb the majority of the sound, but an infected ear will reflect more soundwaves.
If an ear infection has not responded well to treatment, a doctor may use tympanocentesis. This procedure involves creating a small hole in the eardrum and draining a small amount of fluid from the inner ear. This fluid can then be tested to determine the cause of the infection.
Infants under 6 months of age need antibiotic treatment to help prevent the spread of infection. Amoxicillin is often the antibiotic of choice.
For children aged 6 months to 2 years, physicians typically recommend monitoring the child without antibiotics, unless the child has signs of a severe infection.
Ear infections will often clear up without treatment, and the only medication necessary is pain management. Antibiotics are only used in more severe or prolonged cases.
The American Academy of Family Physicians (AAFP) recommend watchful waiting for:
- children aged 6 to 23 months who have experienced mild inner ear pain in one ear for less than 48 hours and a temperature of less than 102.2° Fahrenheit (39° Celsius)
- children aged 24 months and over with mild inner ear pain in one or both ears for less than 48 hours and a temperature of less than 102.2°F
For children older than 2 years, antibiotics are not normally prescribed. Overuse of antibiotics leads to antibiotic resistance. This can mean that serious infections become more difficult to treat.
The AAFP recommend pain management medicine for persistent infections, including acetaminophen, ibuprofen, or eardrops. These help with fever and discomfort.
A warm compress, such as a towel, may soothe the affected ear.
If ear infections continue with recurring episodes over several months or a year, the doctor may suggest a myringotomy. In this procedure, a surgeon makes a small cut in the eardrum, enabling the release of built-up fluid.
A very small myringotomy tube is then inserted to help air out the middle ear and prevent further fluid buildup. These tubes are left in place for 6 to 12 months and will often naturally fall out instead of needing manual removal.
Ear infections are extremely common, especially among children. This is due to an immature immune system and differences in the anatomy of the ear. There is no guaranteed way to prevent infection, but there are a number of recommendations that will reduce the risk:
- Vaccinated children are less likely to get ear infections. Ask a physician about meningitis, pneumococcal, and flu vaccinations.
- Wash your hands and your child's hands often. This prevents potentially spreading of bacteria to your child and can help prevent them catching colds and flu.
- Avoid exposing a child to second-hand smoke. Infants who spend time around people who are smoking more likely to get ear infections.
- Breastfeed infants where possible. This helps enhance their immunity.
- When bottle-feeding an infant, feed them sitting up to reduce the risk of milk flowing into the middle ear. Do not let a baby suck on a bottle while they are lying down.
- Avoid letting your child play with sick children, and try to minimize their exposure to group care or large groups of children.
- Do not use antibiotics unless necessary. Ear infections are more likely in children who have had an ear infection within the previous 3 months, especially if they were treated with antibiotics.
Ear infections are a part of most people's childhood. They can be painful and debilitating, but they present very few long-term problems if properly managed.