Otitis media is swelling or inflammation of the middle ear. The middle ear is usually filled with air although, sometimes, for example during a cold it gets filled with fluid or mucus.  If this fluid gets infected with bacteria it causes an ear infection.

Otitis media is one of the most common childhood infections and is a major cause of illness in children. Almost 80% of children have at least one episode of acute otitis media by the age of three years. Before the introduction of routine vaccination, pneumococcal infection was also estimated to be responsible for half of all cases of acute bacteria otitis media.

Signs and symptoms Children with pneumococcal acute otitis media usually have pain in the infected ear and can have purulent drainage (pus) following perforation of the ear drum. They may also present with fever, vomiting, diarrhoea and temporary hearing loss.

There are three main types of ear infection:

Acute otitis media

Is the most common ear infection, fluid is trapped behind the eardrum and parts of the middle ear are infected and swollen. The term "acute" refers to a short and painful episode.

Otitis media with effusion

Commonly referred to as glue ear, is caused by a build-up of fluid in the middle ear with no symptoms or signs of infection and usually follows an episode of acute otitis media.

Chronic otitis media

An ear infection that lasts a long time or comes and goes is called “Chronic otitis media”. The inflammation or infection of the middle ear that persists or keeps coming back, and can cause long-term or permanent damage to the ear.

The pneumococcus is the most common bacterial cause of otitis media, responsible for over half of bacterial cases. The pneumococcus has also been shown to be a major cause of recurrent otitis media.

Children who develop otitis media usually recover completely, but some develop chronic serious otitis media with fluid in the middle ear. This can impair hearing at the age when speech is developing, potentially compromising educational attainment and linguistic skills. In the worst cases, otitis media can lead to deafness.

Key points

• Otitis media is swelling or inflammation of the middle ear
• Almost 80% of children have at least one episode of acute otitis media by the age of three years
• Otitis media can be defined as: acute otitis media, otitis media with effusion or chronic otitis media
• In the worst cases, otitis media can lead to deafness.