Chronic otitis media (COM) is a chronic infection of the middle ear cavity. It is caused by an ongoing inflammatory response within the middle ear (with granulation), and is typically associated with unresolved and resistant bacterial infections.
There are many terminologies associated with chronic otitis media, which relate to different aetiologies:
Recurrent AOM is the most common cause of COM. Other associated risk factors include traumatic perforation of the TM, insertion of grommets, and craniofacial abnormalities.
Patients will present with a chronically discharging ear(for >6 weeks), in the absence of fever or otalgia. If fever or pain is present then other diagnoses should be considered, such as otitis externa, mastoiditis or intracranial involvement.
On examination, the tympanic membrane will be perforated (Fig. 2); it is important to note the location of the perforation due to the potential risk for cholesteatoma formation. Patients will often have a history of recurrent AOM, previous ear surgery or trauma to the ear.
It is important to test facial nerve function and document this clearly. Hearing loss can occur, which is nearly always conductive hearing loss, unless the disease is extensive
Audiograms and tympanometry should be performed, although this is not possible in a heavily discharging ear. Swabs can be useful in cases of treatment failure.
Whilst the diagnosis of COM is made clinically, any suspicion of cholesteatoma warrants a CT scan of the petrous temporal bone for further assessment.
The mainstay of treatment is aural toileting and topical antibiotic/steroid treatments until symptoms reduce or resolve. Any suspected cholesteatoma should be urgently investigated further.
Patients with symptoms lasting >6 weeks or those with large amounts of debris should be seen by an ENT specialist. The patient should be counselled on the importance of keeping the ear clean and dry.
Most TM perforations will heal spontaneously however large perforations may persist and referral for potential surgical management may be required.
Surgical treatment options are available but the success rate of surgical repair is dependent on the size and site of the perforation. The aim of closing a perforation is to relieve symptoms of persistent discharge and prevent recurrent infection.
Surgery can potentially improve hearing, although this will largely depend on the pre-operative state of the auditory apparatus. The main aim for surgery however is to obtain a dry ear. Surgical options include: