CHRONIC OTITIS MEDIA

  • Chronic Otitis Media

    • 25 Mar 2020
    • Posted By : Dr. Hitesh B. Shah

    Overview

    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.

    Terminology

    There are many terminologies associated with chronic otitis media, which relate to different aetiologies:

    • Mucosal COM chronic inflammation secondary to a perforation (Fig. 1)
    • The cause of the initial perforation may be infective, iatrogenic (e.g. grommet insertion), or trauma
    • o Any associated discharge from the perforation is termed an ‘active’ mucosal COM, also known as ‘Chronic Suppurative OM’ (CSOM)
    • A dry perforation is referred to as ‘inactive’ mucosal COM
    • Squamous COM discharge due to a cholesteatoma (see end of article)
    • Perforations deemed as ‘safe’ are those in the tubotympanic (anteroinferior) part of the tympanic membrane, as they carry a low risk of cholesteatoma
    • ‘Unsafe’ perforations are in the atticoantral (posterosuperior) aspect of the tympanic membrane, as they are associated with high risk of cholesteatoma

    Risk Factors

    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.

    Clinical Features

    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

    Investigations

    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.

    Management

    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 Management

    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:

    • Myringoplasty closure of perforation in pars tensa
    • The closure is achieved by patching on an autologous graft, usually harvested from the tragal cartilage or temporalis fascia.
    • Tympanoplasty a myringoplasty combined with reconstruction of the ossicular chain