Ear infections

The ear has three parts. The outer ear includes the part you can see and the canal that leads to the eardrum. The middle ear is separated from the outer ear by the eardrum and contains tiny bones that amplify sound. The inner ear is where sounds are translated into electrical impulses and sent to the brain.

Any of these three parts can become infected by bacteria, fungi or viruses. Children are particularly prone to middle ear infections (otitis media). It is estimated that around four out of five children will have a middle ear infection at least once.

Symptoms of ear infections#

The symptoms of an ear infection depend on the type, but may include:

• earache
• mild deafness, or the sensation that sound is muffled
• ear discharge
• fever
• headache
• loss of appetite
• itchiness of the outer ear
• blisters on the outer ear or along the ear canal
• noises in the ear, such as buzzing or humming
• vertigo (loss of balance)

How the Eustachian tube works#

The ear is connected to the back of the nose by the Eustachian tube. This tube equalizes air pressure inside the ear and funnels secretions from the middle ear into the throat. Normally the walls of the tube lie flat against each other to stop bacteria and other germs migrating into the ear from the nose and throat. Whenever we swallow, a small muscle flexes and opens the tube, allowing air pressure to equalize and secretions to drain.

If the Eustachian tube is blocked, secretions and the bacteria they carry build up inside the middle ear. This can cause ear infections, mild deafness and an increased likelihood of a ruptured eardrum.

Causes and risk factors#

Some of the many causes of ear infection and contributing risk factors include:

• upper respiratory tract infections
• sudden changes in air pressure, such as during air travel
• smaller than average Eustachian tubes, or a blocked Eustachian tube
• cleft palate
• young age, as babies and children are more prone to ear infections
• swimming in polluted water
• failing to dry the outer ear properly after swimming or bathing
• overzealous cleaning of the ears, which can scratch the delicate tissues

How ear infections are diagnosed#

Ear infections are diagnosed by physical examination and laboratory analysis of any pus or discharge. In some cases CT scans may also be taken.

Types of ear infection#

Types of ear infection include otitis externa, otitis media (acute or chronic), serous otitis media, infectious myringitis, acute mastoiditis, vestibular neuronitis and herpes zoster of the ear.

Otitis externa#

Otitis externa is an infection or inflammation of the ear canal between the eardrum and the outer ear. It can be triggered by exposure to dirty water or by mechanical damage from overzealous cleaning. The infectious agent can be either fungal or bacterial.

Treatment options include:

• keeping the ears dry
• professional cleaning of the ear canal, although syringing the ear should usually be avoided
• eardrops containing antibiotics and steroids, if the infection is bacterial
• oral antibiotics
• eardrops containing antifungal medications and steroids, if the infection is fungal
• pain-relieving medications

Otitis media#

Otitis media is an infection of the middle ear, which can be acute or chronic. Children are most commonly affected by acute otitis media because it is caused by colds and blocked Eustachian tubes, both typical of childhood. The infectious agent can be viral or bacterial, with research suggesting that viruses are responsible for most cases. Sometimes the eardrum bursts, leading to pus in the ear canal, but usually it heals by itself.

Treatment options include:

• pain-relieving medications
• antibiotics, if the infection is bacterial
• eardrops, if there is pus in the ear canal

Frequent bouts of acute otitis media, or one lingering attack, can lead to chronic otitis media. Without treatment, the chronic infection can burst the eardrum or damage the delicate structures within the middle ear. Other possible complications of untreated chronic otitis media include meningitis, infection of the balance organs within the ear (labyrinthitis), sensorineural deafness (permanent hearing loss) and paralysis of the face.

Treatment options for chronic otitis media include:

• thorough cleaning of the ear and use of topical antibiotic drops (with or without steroids)
• medication to treat the infection
• surgical repair of the perforated eardrum
• prevention strategies to reduce the risk of another infection

Serous otitis media (glue ear)#

Serous otitis media is known as glue ear. Children aged between six months and two years are most vulnerable to this type of infection. Glue ear commonly develops after a middle ear infection and is marked by a build-up of fluid and pus within the middle ear.

Treatment options include antibiotics. If antibiotics fail, or if the child has repeated attacks of glue ear, surgery to insert small drainage tubes (grommets) may be needed.

Infectious myringitis#

Infectious myringitis is inflammation of the eardrum, caused by infection from viruses or bacteria. The eardrum responds by forming small blisters, which can be quite painful. If fever is present, the infectious agent is almost certainly bacterial.

Treatment options include:

• antibiotics
• pain-relieving medications
• professional rupturing of the blisters

Acute mastoiditis#

The bone that can be felt immediately behind the ear is called the mastoid. Acute mastoiditis is an infection of this bone, caused by prior acute otitis media. The symptoms include reddened and swollen skin over the mastoid, fever, discharge from the ear and intense pain.

This is a serious condition. Untreated, acute mastoiditis can lead to deafness, blood poisoning, meningitis and paralysis of the face.

Treatment options include:

• intravenous antibiotics
• surgical drainage of the infected bone

Vestibular neuronitis#

The inner ear contains the organs of balance, the vestibular system. It includes three fluid-filled loops (semi-circular canals) that respond to rotation of the head. Near them are the utricle and saccule, which detect gravity and back-and-forth motion. When the head moves, signals from these organs are sent via the vestibular nerve to the brain to be processed.

Vestibular neuronitis is inflammation of the vestibular nerve, probably caused by a viral infection. The main symptom is sudden and dramatic vertigo, which may come with nausea and vomiting. The eyes may also involuntarily flutter towards the affected side of the head.

Treatment options include:

• medications, including antihistamines
• anti-nausea medications
• vestibular physiotherapy, to help the brain compensate or retrain

Herpes zoster of the ear#

Sound is sent as electrical impulses to the brain via the cochlear nerve. Herpes zoster of the ear is an infection of this auditory nerve by the herpes zoster virus. Symptoms include ear pain, vertigo and small blisters on the outer ear, ear canal and perhaps the face. The main nerve serving the facial muscles may also become infected, leading to swelling and partial paralysis.

Treatment options include:

• pain-relieving medications
• antiviral medications and steroids, such as acyclovir

Key points#

• The ear can be infected by bacteria, fungi or viruses, and children are especially prone to middle ear infections.
• Symptoms depend on the type of infection and can include earache, mild deafness, discharge, fever and vertigo.
• A blocked Eustachian tube can cause ear infections, mild deafness and a greater risk of a ruptured eardrum.
• Treatment depends on the type of infection and may include keeping the ears dry, eardrops, antibiotics, antiviral medication, pain relief and surgery.
• Some infections, such as chronic otitis media and acute mastoiditis, can be serious if left untreated.

Where to get help#