Chronic ear infection is inflammation or infection of the middle ear that persists or keeps coming back, and causes long-term or permanent damage to the ear.

See also: Acute ear infection

For each ear, a eustachian tube runs from the middle ear to the back of the throat. This tube drains fluid that is normally made in the middle ear. If the eustachian tube becomes blocked, fluid can build up. When this happens, germs such as bacteria and viruses can multiply and cause an infection. This is called an acute ear infection (acute otitis media).

A chronic ear infection occurs when fluid or an infection behind the eardrum does not go away. A chronic ear infection may be caused by an acute ear infection that does not clear completely, or repeated ear infections. Fluid in the middle ear may become very thick. Sometimes, the eardrum (tympanic membrane) may stick to the bones in the middle ear.

A chronic ear infection may cause permanent changes to the ear and nearby bones, including:

• Infection in the mastoid bone behind the ear (mastoiditis)
• Ongoing drainage from a hole in the eardrum that does not heal, or after the ear tubes (tympanostomy tubes) are inserted
• Cyst of the middle ear (cholesteatoma)
• Hardening of the tissue in the middle ear (tympanosclerosis)
• Damage to, or wearing away of the bones of the middle ear, which help with hearing

"Suppurative chronic otitis" is a phrase doctors use to describe an eardrum that keeps rupturing, draining, or swelling in the middle ear or mastoid area and does not go away.

Ear infections are more common in children because their Eustachian tubes are shorter, narrower, and more horizontal than in adults. Chronic ear infections are much less common than acute ear infections.