Clinical features

The main symptom of chronic suppurative otitis media is of persistent or frequently recurring discharge from the ear. The discharge is usually purulent (consisting of pus) and may have an offensive smell.

Pain may occur but is less significant than in acute otitis media and there may be no pain. Perforation of the eardrum is present and it is this that allows the pus from the middle ear to escape into the external ear canal. The perforation reduces the amplifying effect of the eardrum and hearing may be impaired.

In severe cases chronic infection can disrupt the chain of ossicles with more profound effect on hearing. Generally there is no significant systemic general illness unless fresh infection superimposes on the chronic inflammation when fever and malaise may occur.

Infection spreading into the cellular passages of the mastoid bone may cause acute mastoiditis and this can spread into the bone itself causing osteomyelitis.

Chronic suppurative otitis media can be associated with a condition called cholesteatoma where growth of granular inflammatory tissue adds to the obstruction within the middle ear cavity and delays healing. Cholesteatoma may also invade local structures including the surrounding bone with destruction of the bony structure. Some patients may experience tinnitus

Spread of infection into the inner ear can result in damage to the auditory sensory organ (cochlea) and cause labyrinthitis. More serious complications can occur from spread of infection through the skull causing meningitis or cerebral abscess.

Perforation of the ear drum (tympanic membrane)

Perforation associated with infection results from a build up of pus and fluid within the middle ear causing the drum to bulge and then burst. The eardrum can also be perforated by trauma from a piercing injury, a blow to the head or ‘barotrauma’ where sudden changes of air pressure also can cause bulging and rupture of the membrane. Barotrauma results from the sudden the increase of air pressure in an explosion, or from sudden changes in atmospheric pressure as can occur in diving or air travel. The latter effects can be avoided by regularly ‘decompressing’ the middle ear by swallowing or blowing against a closed nose and mouth to force open the eustachian tube.

Perforation can occur at several locations within the membrane:

• Marginal perforation occurs when the membrane separates along its edge from the bony rim to which it is attached.
• Central perforation occurs when a gap appears within the main membrane but a rim of tissue remains intact and not separated from the bone.
• Attic perforation occurs in a very small part of the membrane that is high up in the cavity immediately above the attachment of one of the ossicles.

Formation of cholesteatoma secondary to the healing process is more commonly associated with attic and marginal perforation.

Tinnitus

Tinnitus is a recurrent or persistent noise perceived in the absence of any stimulation by sound (ringing in the ears). It is a subjective experience, which can neither be observed by another person nor measured.

The noise perceived might be described as a buzzing, ringing, hissing, whistling or roaring sound which may vary in intensity and with time. It may be continuous or intermittent and may be synchronous with the pulse beat.

Tinnitus can accompany any disorder of the ear including simple problems such as wax or foreign body in the external ear canal. It commonly occurs in association with inner ear disease or sensorineural damage to the ear. It may also accompany the effects of general systemic diseases and has been recognised as a feature in cardiovascular disease, hypothyroidism and anaemia. It can result from the toxic effect of some substances, particularly drugs that are toxic to the inner ear (ototoxic) such as aspirin, quinine and some antibiotics (particularly streptomycin).

Amended February 2009