Middle Ear Infection
What is a middle ear infection?
A middle ear infection, otherwise known as otitis media, is a viral or bacterial infection of the air-filled cavity behind the eardrum. In most cases, a middle ear infection affects just one ear, but can also occur in both ears simultaneously. The infection can cause painful inflammation, as well as a build-up of fluid in the middle ear. Although people of any age can develop the infection, it is most common in younger children, with a high percentage of children experiencing the condition before the age of 10.
In some cases, a middle ear infection may disappear without treatment. While antibiotics are only sometimes necessary to fight the infection, pain-relievers are commonly prescribed to lessen the pain caused by the condition. Further treatment options are available for recurrent middle ear infections. Complications are rare, meaning it is generally considered a non-serious condition.
There are three common types of middle ear infection:
- Acute otitis media: This is the most common form. It is characterised by its rapid onset and often results in ear pain, fever and hearing impairment. It usually lasts for between a few days and a few weeks.
- Otitis media with effusion: Once the initial infection has faded, non-infectious fluid or mucus may continue to build, resulting in pronounced hearing loss and a feeling of fullness in the ear. Otitis media with effusion can also result from a fluid build-up that was never infected. In such cases, antibiotics will often not work as a treatment method. This form often lasts longer than acute otitis media; running its course after around four to six weeks.
- Chronic otitis media: An acute middle ear infection with or without effusion that does not fully disappear or repeats frequently. This can lead to a prolonged inflammatory reaction with subsequent fluid build-up and often to a tear or perforation in the ear drum. When this happens, there will also be discharge from the middle ear. Chronic otitis media can lead to long-term hearing impairment.
Symptoms of a middle ear infection
A middle ear infection generally develops very rapidly.
Signs and symptoms in children may include:
- Ear pain
- Generally feeling unwell (malaise)
- Muffled hearing/partial hearing loss
- Fluid in the ear or yellow, clear or bloody discharge from the ears
- Increased irritability, restlessness, crying and trouble feeding
- Nausea, vomiting and/or dizziness
- A child may excessively pull, tug or touch their ears
Symptoms of a middle ear infection in adults may include:
- Ear pain
- Partial hearing loss/muffled hearing
- Fluid in the ear (that may leak out) or yellow, clear or bloody discharge from the ears
It is important to consult a doctor when:
- Symptoms develop in a child of six months or younger
- A child displays symptoms for 48 hours or more and has a temperature of 39 C (102.2 F) or more
- Symptoms show no sign of improvement after two or three days
- Symptoms become worse rather than better over the first few days
- Discharge presents itself
- Symptoms are experienced by a person with an underlying health condition, such as cystic fibrosis or congenital heart disease, which could make complications more likely
Causes of a middle ear infection
Middle ear infections are caused by viruses and bacteria, often resulting from other conditions (flu, cold, allergy) that can cause blockage and swelling of the eustachian tubes that connect the throat and the middle ear. When this happens, a vacuum is created, allowing germs and fluid from the throat to enter the middle ear. A middle ear infection develops when bacteria or viruses grow in this fluid.
Children are more susceptible to middle ear infections than adults, partly because their eustachian tubes are narrower, so they are more easily blocked. Children also have relatively larger adenoids than adults. These are masses of tissue situated at the point where the nose bends into the throat that are vulnerable to infection, swelling and inflammation – when this happens, they can block the eustachian tubes and cause a middle ear infection.
Diagnosing a middle ear infection
A doctor will generally be able to diagnose a middle ear infection by considering a person's symptoms and looking for specific signs. Using an otoscope (a lighted wand-like instrument), a doctor will be able to look into the ears, throat and nose for any signs of infection. While the area around the eardrum will most likely be red and swollen, this will normally only be noticeable upon examination with an otoscope. The ear itself will generally not be red or swollen.
In some cases, especially when the condition is predicted to have taken the form of otitis media with effusion, a pneumatic otoscope may be used to confirm a diagnosis. This instrument pumps air into the middle ear and measures the resulting pressure changes. If little response is felt, this indicates the presence of fluid in the ear.
To further confirm a middle ear infection diagnosis, a doctor may order a number of further tests, including:
- Tympanometry: By testing the movement of the eardrum, this test can provide an indirect measure of pressure and fluid build-up behind the eardrum
- Acoustic reflectometry: By emitting sound into the eardrum and measuring the response from the eardrum, the amount of fluid in the eardrum can be measured. The more sound is reflected by the eardrum, the more fluid is present in the middle ear
- Tympanocentesis: If a middle ear infection is persistent, this test can be used to determine what kind of bacteria is present. This is done by piercing the eardrum, draining the fluid and then testing the make-up of this fluid
Middle ear infection treatment
In many cases, no treatment is required for a middle ear infection, with the symptoms fading quickly and the infection clearing up completely in anywhere between a number of days and two weeks. However, if the symptoms are severe or the infection is persistent, treatment methods are available.
Over-the-counter pain relief medication such as ibuprofen and acetaminophen (paracetamol) can be used by those experiencing a middle ear infection. When giving these drugs to children, a medical professional should be consulted first. Adults should read the instructions on the packaging closely before taking medicinal pain relief. For less severe pain, or if pharmaceuticals are not an option, a warm compress over the ear can also help relieve pain.
In children, antibiotics will normally be prescribed when:
- The infection is severe
- The child is younger than two years old, has an infection in both ears and has mild to severe pain and fever
- The child is at risk of complications from the infection
In cases outside of these parameters, doctors will generally wait a few days before prescribing antibiotics. Adults will typically be prescribed antibiotics when the symptoms are severe or when the infection does not disappear naturally.
When taking antibiotics, it is extremely important to follow the exact instructions of the doctor or pharmacist and ensure the full course is taken. Failure to do so can result in a recurrence of the problem and in the development of antibiotic resistance in the bacteria causing the infection.
Ear tubes (grommets)
If an individual experiences persistent middle ear infections (generally defined as three episodes in six months or four in a year) then ear tubes – sometimes known as grommets – may be necessary.
To place these, a small hole is created in the eardrum. Through this, fluid is drained and a tube is fitted to ventilate the middle ear and prevent the further buildup of fluids. Some ear tubes will naturally fall out after a number of months, whereas others are designed to be worn for longer and may require a procedure in order to remove them. Both the initial insertion and the removal are relatively straightforward outpatient procedures.