Description

• The tympanic membrane, or eardrum, is a thin barrier that separates the external auditory canal from the middle ear and vibrates in response to sound waves, thus providing an important link in the hearing pathway.
• Rupture of the tympanic membrane disrupts hearing and creates an opening between external auditory canal and the middle ear.
• Perforations are classified by location:
  • Central or those not involving the annulus are typical after a case of acute otitis media that leads to perforation.
  • Marginal involve the annulus and are frequently associated with cholesteatoma and are thus less likely to heal spontaneously.
  • Subtotal: A large defect surrounded with an intact annulus; often requires surgery to close
• Classification of perforations by etiology:
  • Acute/Chronic suppurative otitis media
  • Traumatic (barotraumas, such as diving, and acoustic trauma, such as explosion) (1)
  • Cholesteatoma
  • Iatrogenic (after extrusion of pressure equalization tubes)
• Spontaneous closure results in formation of a double skin layer (outer epidermal and inner mucosal), whereas inability to do so results in a chronic perforation.

Epidemiology

Incidence in the general population is unknown, since many perforations heal spontaneously.

Risk Factors

• Chronic eustachian tube dysfunction leading to otitis media with effusion (OME)
• Insertion of foreign objects into external ear canal (e.g., cotton swabs, pressure equalization tubes)

Genetics
Genetic susceptibility has been reported for recurrent acute otitis media (AOM) and chronic otitis media with effusion (COME), 2 of the etiologies of perforations (2).

General Prevention

• Avoid ear trauma and foreign object insertion into external ear canal.
• Treat otitis media in a timely fashion.

Pathophysiology

• Chronic eustachian tube dysfunction or chronic negative middle-ear pressure
• Insertion of foreign objects into ear (cotton swabs)
• Otitis media: A purulent, serous, or mucoid fluid builds up behind the tympanic membrane.
• A ruptured tympanic membrane that does not heal is often due to cholesteatoma.

Etiology

• Suppurative otitis media or middle ear infection leading to pressure buildup from pus and the resulting rupture of the tympanic membrane
• Direct trauma from foreign body (cotton swabs, pencils, direct blows to the head, etc.), barotraumas, or temporal bone fracture
• Insertion of foreign objects into ear
• Iatrogenic: For the treatment of chronic eustachian tube dysfunction, a myringotomy is performed and tympanostomy tubes are placed; after tubes are extruded, a chronic perforation may result.

Commonly Associated Conditions

• Chronic eustachian tube dysfunction
• OME
• Cholesteatoma
• Tympanosclerosis
• Ossicular chain damage