Diseases of the tympanic membrane - I

Causes:

• Indirect trauma: Due to rapid pressure changes:

• A blow on the ear (commonest).

• Otitic barotrauma.

• Blast injury (explosion).

• Sudden fluid compression in jumping in swimming pool.

• Over inflation of the Eustachian tube by forcible nose blowing.

• Direct trauma:

• Foreign body.

• Slag burns (hot metal particles enter the external canal during welding  perforation of the tympanic membrane).

• Self-inflicted e.g. by a hairpin.

• Unskilled ear wash or instrumentation.

• Longitudinal fracture of temporal bone ( attic perforation).

Clinical picture:

History of the cause followed by:

1. Earache: transient at the time of rupture.

2. Bloody otorrhoea: mild and transient at the time of rupture.

3. Hearing loss and Tinnitus.

4. Air escapes out of the ear on blowing of the nose producing whistling sound.

5. Perforation occurs commonly in pars tensa. It usually locates in the antero-inferior quadrant (in indirect trauma as slap), irregular in shape, has hyperaemic edges and is surrounded by blood clots. In self-inflicted cases, the perforation is posteroinferior.

6. Tuning fork tests: conductive hearing loss.
   

Complications:

1. Otitis media.
   
2. Permanent drum perforation.
3. Ossicular dislocation.
   
4. Implantation cholesteatoma.

Treatment:

1. Conservative treatment: For three months waiting for the possibility of spontaneous healing. It includes:

   1. Prophylactic antibiotic therapy.

   2. Decongestant nasal drops.

   3. Avoid ear contamination.

   4. Do not wash the ear.

   5. Do not use eardrops.

   6. Do not blow the nose forcibly.

2. Surgical treatment: Myringoplasty (i.e. repair of tympanic membrane perforation by a graft taken from temporalis fascia), when the perforation fails to heal after three months.
   
   

Differential diagnosis: Tympanic membrane perforation due to chronic suppurative otitis media.

Category: ENT Notes