What is a middle ear infection?

Acute otitis media is the term for middle ear infections caused by viruses or bacteria. It’s usually associated with an upper respiratory tract infection. Viruses travel from the nose and throat area through the auditory tube to the middle ear. The auditory tube, known as the Eustachian tube, helps maintain equal air pressure on both sides of the eardrum and is responsible for middle ear ventilation. The middle ear is an air-filled space behind the eardrum that contains three tiny bones known as the ossicles—malleus, incus, and stapes. The function of the middle ear is to carry sound energy through the air to the liquid-filled cochlea in the inner ear.

What are the symptoms of a middle ear infection?

The most common symptoms in adults include:

  • Earache
  • Muffled hearing
  • Fluid discharge from the ear

Middle ear infection commonly occurs in childhood and children up to the age of 6 years are often affected. The following signs in babies or children may indicate an infection:

  • Earache
  • Fever of 38℃ or higher
  • Touching the ear or tugging at it
  • Dizziness or loss of balance
  • Trouble hearing
  • Stomach pain
  • Headache

Babies and young children are the most susceptible to middle ear infections. Exposure to tobacco smoke can increase the risk. Breast-fed babies tend to be largely unaffected.

Complications of middle ear infections

It rarely happens, but if left untreated, middle ear infections can cause serious complications. The infection can spread to the mastoid process, a cone-shaped part of the temporal bone behind the ear (mastoiditis). It can also spread to the central nervous system and result in an inflammation of the membranes that protect the brain and spinal cord (meningitis). Frequent infections can lead to tearing or scarring of the eardrum, damage to the ossicles and, ultimately, permanent hearing loss. It can also cause facial nerve paralysis.

How is a middle ear infection diagnosed and treated?

A specialist will examine the eardrum with an otoscope to determine what kind of treatment is necessary. In addition to pain management and decongestants like nasal sprays, antibiotics are often prescribed. Immune-compromised patients and those who do not respond to antibiotics treatment are subjected to smear and bacteriological tests to identify the pathogen and prescribe targeted antibiotics.

In some cases, the doctor has to perform a small incision in the eardrum. This is done under local anaesthesia to allow the accumulated fluid to drain. A hearing test performed to diagnose an acute middle ear infection would first reveal conductive hearing loss.

A specialist will also look at other possible causes of an earache, such as allergies and diabetes.

Quick info

Common pathogens associated with middle ear infections
  • Streptococcus pneumoniae (bacteria that cause pneumonia)
  • Haemophilus influenzae (bacteria that cause influenza or the flu)
  • Group A streptococcus (bacteria that cause strep throat)
Middle ear infection and hearing aids

Hearing aids cannot cause middle ear infection, but if hearing aid wearers frequently suffer from a middle ear infection, it’s important to leave the ear canal open for proper ventilation. We would recommend wearing a behind-the-ear device with an external receiver.

In rare cases, a middle ear infection can cause permanent hearing loss. Hearing aids can help you regain your quality of life.