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Chronic suppurative otitis media

Theresa Erasmus, MMed ORL

Senior Specialist, Department of Otorhinolaryngology, University of the Free State, Bloemfontein

Correspondence to: T Erasmus (gnolte@ufs.ac.za)

Chronic suppurative otitis media (CSOM) is a stage of ear disease in which there is chronic infection of the middle-ear cleft, i.e. the eustachian tube, middle ear and mastoid, and in which a non-intact tympanic membrane (e.g. perforation or tympanostomy tube) and discharge (otorrhoea) are present.1 The perforation can result as a complication or as sequelae of acute otitis media, trauma or extrusion or removal of a tympanostomy tube.1 Prevalence surveys, which vary widely in disease definition, sampling methods and methodological quality, show that the global burden of illness from CSOM involves 65 - 330 million individuals with draining ears, 60% of whom (39 - 200 million) suffer from significant hearing impairment.2

Clinical picture

Patients with CSOM may consult a doctor with one of the following:2

• a newly discharging untreated ear

• a persistently discharging initially treated ear

• a recurrently discharging ear

• a discharging ear with headache, fever, dizziness and other danger signs, or

• a dry, perforated eardrum with hearing loss.

The first two conditions can be treated at primary care level, with dry ear mopping and appropriate topical antimicrobials. A swab can be taken to confirm the organisms involved. Referral for specialist treatment is indicated in cases of suspected complications, cases not responsive to treatment or cases of hearing loss (Fig. 1).

Microbiology

The organisms involved differ from those implicated in acute otitis media and include aerobic organisms, predominantly Staphylococcus aureus and Pseudomonas aeruginosa (Proteus spp. in a local study) as well as anaerobic organisms of which Peptostreptococcus spp. occur most commonly.3

Treatment

The aims of treatment are to clear up the otorrhoea, close the tympanic membrane perforation, improve the hearing loss and prevent complications. In a Cochrane review undertaken in 2005, it was found that topical antibiotics are more effective in treating discharging ears with an underlying perforation than either systemic antibiotics or topical antiseptics.4 The introduction of quinolone eardrops in 1998 heralded a new era in ototopic treatment, largely replacing gentamycin-containing drops with their well-known ototoxic potential.5 Surgery is often needed.

Cholesteatoma

Cholesteatoma is a destructive lesion consisting of keratinising stratified squamous epithelium in the middle ear and/or mastoid. It should be suspected in cases of offensive otorrhoea, cases not responding to appropriate treatment and in those with complications. The definitive treatment for cholesteatoma is surgical, the extent of disease dictating the type of procedure indicated.

Complications

Although complications have decreased since the introduction of antibiotics early in the 20th century, they continue to occur, and can be lethal if they are not identified and treated properly.

Extracranial complications

Subperiosteal abscess, also referred to as acute mastoiditis, is the most common complication of CSOM and can occur with or without the presence of a cholesteatoma. The abscess occurs over the mastoid cortex when the infectious process within the mastoid air cells extends into the subperiosteal space. The diagnosis of a subperiosteal abscess is often made clinically. Commonly, the patient will present with systemic symptoms, including fever and malaise, along with local signs, such as a protruding auricle that is laterally and inferiorly displaced, and the presence of a fluctuant, erythematous, tender area behind the ear. A CT scan might be indicated to evaluate the extent of the disease and help in therapeutic planning, exclude intracranial complications or confirm the diagnosis in uncertain cases.6 Treatment includes incision and drainage of the abscess in conjunction with intravenous antibiotics as well as ear toilet and topical treatment. Whether or not a cortical mastoidectomy should be performed in all cases is controversial. Surgery would certainly be indicated in patients with underlying cholesteatoma, but this may be delayed (Fig. 2).

Other extracranial complications include Bezold’s abscess, labyrinthine fistulae, facial nerve paralysis and petrous apicitis (Gradenigo’s syndrome).6

Intracranial complications

Meningitis is the most common intracranial complication of acute and chronic otitis media. Signs that should increase the suspicion of an intracranial complication include persistent or intermittent fever, nausea and vomiting, irritability, lethargy, or persistent headache. Ominous signs virtually diagnostic of an intracranial process include visual changes, new-onset seizures, nuchal rigidity, ataxia, or decreased mental status. If any of these suspicious or ominous signs occur, immediate treatment and further work-up are critical. Broad-spectrum antibiotics, such as third-generation cephalosporins, should be administered while diagnostic tests are ordered and arranged. A contrasted CT scan or an MRI will show characteristic meningeal enhancement and rule out additional intracranial complications known to occur in up to 50% of these cases. In the absence of a significant mass effect on imaging, a lumbar puncture should be performed to confirm the diagnosis and to allow for culture and sensitivity testing.6

Other intracranial complications are brain and epidural abscesses, lateral sinus thrombosis and otitic hydrocephalus.6

References

1. Bluestone CD. Epidemiology and pathogenesis of chronic suppurative otitis media: implications for prevention and treatment. Int J Pediatr Otorhinolaryngol 1998;42: 207-223.

2. WHO. Chronic Suppurative Otitis Media Burden of Illness and Management Options. Geneva: World Health Organization, 2004.

3. Brook I. The role of anaerobic bacteria in chronic suppurative otitis media in children: Implications for medical therapy. Anaerobe 2008;14:297-300.

4. Macfadyen CA, Acuin JM, Gamble CL. Systemic antibiotics versus topical treatments for chronically discharging ears with underlying eardrum perforations (Review). The Cochrane Library 2006, Issue 1, Art. No.: CD005608. [http://dx.doi.org/10.1002/14651858]

5. Haynes DS. Topical antibiotics: Strategies for avoiding ototoxicity. Ear Nose Throat J 2004;83(Suppl.1):12-14.

6. Smith JA, Danner CJ. Complications of chronic otitis media and cholesteatoma. Otolaryngol Clin N Am 2006;39:1237-1255.