Chronic Suppurative Otitis Media

Chronic inflammation of the middle ear cleft and mastoid with a persistent tympanic membrane perforation and recurrent or continuous otorrhoea. Definitions of duration vary, with discharge for more than 2 weeks used in some settings and 3 months in others. It remains one of the leading causes of preventable hearing loss worldwide and carries the entire burden of otogenic intracranial complications in low resource settings.

Two clinical entities with entirely different risk profiles

• Mucosal, tubotympanic or safe disease: a central perforation of the pars tensa with an intact annulus, mucosal inflammation, intermittent mucoid discharge usually triggered by upper respiratory infection or water entry, and a low risk of intracranial complication.
• Squamous, atticoantral or unsafe disease: an attic or marginal perforation or retraction pocket with keratinising squamous epithelium in the middle ear, that is cholesteatoma, with scanty foul discharge, granulation tissue and progressive bone erosion. This group produces the complications.

The safe and unsafe terminology is clinically useful but not absolute. Mucosal disease with extensive granulation and osteitis can also erode bone, and complications occur in both groups.

Microbiology

• Pseudomonas aeruginosa and Staphylococcus aureus predominate.
• Proteus mirabilis, Klebsiella and Escherichia coli are frequent.
• Anaerobes including Bacteroides and Peptostreptococcus in foul smelling discharge and in cholesteatoma.
• Fungal superinfection with Aspergillus and Candida, especially after repeated antibiotic drops.
• Mycobacterium tuberculosis in painless disease with multiple perforations, pale granulation, disproportionate hearing loss including a sensorineural component, and early facial palsy. Consider it particularly in HIV endemic settings and in any ear that fails to respond to standard treatment.

Pathophysiology of hearing loss

Conductive loss of 20 to 40 dB from the perforation, worsening to 50 to 60 dB with ossicular erosion, most commonly of the long process of the incus, which has a tenuous blood supply. Cholesteatoma erodes the incus, then the stapes superstructure and the scutum. A sensorineural component develops over time from bacterial toxin and inflammatory mediator diffusion through the round window, which is one of the arguments for definitive surgery rather than indefinite medical management.

• Painless, persistent or intermittent otorrhoea. Pain is not a feature of uncomplicated disease and its appearance signals a complication.
• Mucoid or mucopurulent discharge in mucosal disease; scanty, thick and foul smelling discharge in cholesteatoma, the odour reflecting anaerobic and osteitic activity.
• Progressive conductive hearing loss.
• Tinnitus.
• Discharge triggered by water exposure or upper respiratory infection in mucosal disease.

Examination under the microscope, which is mandatory

• Site of the perforation. A central pars tensa perforation with a visible rim indicates mucosal disease. An attic defect, a posterosuperior marginal perforation, or a retraction pocket whose base cannot be seen indicates squamous disease.
• Keratin flakes, granulation tissue and aural polyps.
• Middle ear mucosa: pale and dry, or oedematous and polypoid.
• Ossicular status where visible.
• Never avulse an aural polyp blindly in the clinic. It may be attached to the stapes, the facial nerve or dura, and traction can produce sensorineural deafness, facial palsy or a cerebrospinal fluid leak. Biopsy the edge or remove under the microscope with knowledge of the anatomy.

Red flags for complication

• Onset of pain or headache in a previously painless ear.
• Vertigo, particularly if provoked by pressure on the tragus or by loud sound, indicating a labyrinthine fistula.
• Facial nerve weakness.
• Fever, rigors, swinging pyrexia and papilloedema, indicating sigmoid sinus thrombosis or otitic hydrocephalus.
• Neck stiffness, altered consciousness, seizure or focal neurology, indicating meningitis or brain abscess.
• Postauricular swelling and fluctuance, indicating subperiosteal abscess.

• Microscopic examination after thorough aural toilet is the single most important diagnostic step. The diagnosis of cholesteatoma is missed when the ear is examined with a hand held otoscope through discharge.
• Swab for aerobic, anaerobic and fungal culture. Send mycobacterial culture and Xpert testing in non resolving disease.
• Pure tone audiometry with masking, documenting the air bone gap and any sensorineural component. Repeat before and after surgery.
• Fistula test in any patient with vertigo. A positive test is nystagmus and vertigo on tragal compression.
• High resolution computed tomography of the temporal bone when cholesteatoma is suspected, before surgery, and whenever a complication is possible. It defines scutum erosion, ossicular status, tegmen and sigmoid plate integrity, lateral semicircular canal fistula, facial canal dehiscence and mastoid pneumatisation.
• Magnetic resonance imaging with non echoplanar diffusion weighted sequences for detection of residual or recurrent cholesteatoma, which appears as a restricted diffusion focus. This has largely replaced routine second look surgery in many centres for lesions above 3 mm.
• Contrast magnetic resonance imaging with venography urgently for suspected intracranial complication.
• Biopsy of granulation or polypoid tissue that does not settle, to exclude tuberculosis, malignancy and granulomatous disease.
• HIV testing and blood glucose.

Differential diagnosis

• Chronic otitis externa with a normal drum obscured by debris.
• Tuberculous otitis media: multiple perforations, pale granulation, early facial palsy, disproportionate hearing loss.
• Squamous cell carcinoma of the middle ear or canal: bleeding, pain, facial palsy, tissue recurring after removal.
• Langerhans cell histiocytosis and granulomatosis with polyangiitis.
• Cholesterol granuloma: blue drum, expansile lesion on imaging.

Mucosal disease with a discharging ear

• Aural toilet is the foundation. Repeated microsuction under the microscope, or dry mopping where microscopy is unavailable, performed at every visit and taught to the family for daily dry mopping.
• Topical quinolone drops are more effective than systemic antibiotics and are the treatment of choice: ciprofloxacin 0.3 percent, with or without dexamethasone, 4 to 5 drops twice daily for 10 to 14 days; or ofloxacin 0.3 percent, 10 drops once daily. These are not ototoxic and are safe with a perforation.
• Aminoglycoside containing drops carry cochleotoxic and vestibulotoxic risk in a perforated ear. Where no alternative exists, limit use to a discharging ear for no more than 2 weeks and stop immediately if vertigo or hearing deterioration occurs.
• Strict dry ear precautions.
• Treat nasal and sinus disease, allergic rhinitis and adenoid hypertrophy, which perpetuate the tubal dysfunction.
• Systemic antibiotics are reserved for cellulitis, systemic illness, complications and topical failure: ciprofloxacin 500 to 750 mg orally twice daily in adults; in children, choose according to culture and specialist advice.
• Reassess at 4 to 6 weeks. Failure to dry after adequate toilet and topical therapy requires computed tomography and reconsideration of cholesteatoma, tuberculosis, fungal infection, osteitis or malignancy.

Surgery for mucosal disease

• Tympanoplasty once the ear has been dry for a period, ideally 3 months, though surgery on a wet ear is often necessary in practice and gives acceptable results when granulation and osteitis are addressed.
• Graft choice as for tympanic membrane perforation: temporalis fascia for standard cases, cartilage with perichondrium for large, anterior, revision, and atelectatic ears.
• Ossiculoplasty with incus interposition or a partial or total ossicular replacement prosthesis with a cartilage interface.
• Cortical mastoidectomy is added when there is a mastoid reservoir of disease, persistent discharge despite treatment, or extensive granulation.

Surgery for squamous disease and cholesteatoma

Cholesteatoma is a surgical disease. Medical treatment only controls infection temporarily.

• Canal wall up, that is combined approach tympanoplasty, preserves canal anatomy and avoids a mastoid cavity but carries a residual and recurrent disease rate of 10 to 20 percent or more, requiring either a second look procedure at 9 to 18 months or magnetic resonance surveillance with non echoplanar diffusion weighted imaging.
• Canal wall down mastoidectomy provides the lowest recurrence rate and is indicated for extensive disease, a labyrinthine fistula, a dehiscent facial nerve with disease around it, an only hearing ear, poor Eustachian tube function, intracranial complications, and patients unlikely to attend surveillance. The cost is a cavity requiring lifelong cleaning and water precautions.
• Mastoid obliteration with bone pate, cartilage or vascularised flaps reduces cavity problems and is increasingly used with canal wall reconstruction.
• Labyrinthine fistula: matrix over a lateral canal fistula is managed either by careful complete removal with immediate sealing using fascia and bone pate, or by leaving matrix over the fistula in an exteriorised cavity. The decision depends on hearing status, fistula size and surgeon experience. Avoid suction directly over a fistula.

Complications and their management

Intratemporal:

• Acute mastoiditis and subperiosteal abscess: intravenous antibiotics with cortical mastoidectomy and drainage.
• Facial nerve palsy: urgent surgery with decompression of the involved segment and removal of disease.
• Labyrinthine fistula and suppurative labyrinthitis: intravenous antibiotics, urgent surgery, and recognition that meningitis may follow.
• Petrositis with the triad of deep retro orbital pain, abducens palsy and otorrhoea.

Intracranial, which carry the mortality:

• Meningitis, extradural abscess, subdural empyema, temporal lobe and cerebellar abscess, sigmoid sinus thrombosis, and otitic hydrocephalus.
• Immediate broad spectrum intravenous therapy with central nervous system penetration: ceftriaxone 2 g intravenously twice daily in adults, or 50 mg/kg twice daily in children, plus metronidazole 500 mg intravenously three times daily in adults or 7.5 mg/kg three times daily in children, with vancomycin added when resistant staphylococci or pneumococci are a concern.
• Urgent contrast magnetic resonance imaging with venography, neurosurgical involvement for abscess drainage, and mastoid exploration to achieve source control. Both must proceed; drainage of an abscess without eradicating the ear disease leads to recurrence.
• Anticoagulation for sigmoid sinus thrombosis remains debated and is decided case by case with neurology and neurosurgery, balancing propagation against haemorrhage.

Long term care and prevention

• Lifelong water precautions in an open cavity, with 6 to 12 monthly microsuction.
• Audiological rehabilitation with a hearing aid, a bone conduction device for a discharging or cavity ear, or a bone anchored device where a conventional mould causes discharge.
• Treat every episode of upper respiratory infection promptly and manage nasal disease.
• Prompt and adequate treatment of acute otitis media, and appropriate management of retraction pockets before cholesteatoma forms, are the only meaningful primary prevention.
• Any ear that discharges despite a technically correct operation requires reassessment for residual cholesteatoma, tuberculosis, fungal infection or malignancy rather than a further course of drops.

Fifty at this depth exceeds what one response can hold without thinning the content. This batch covers 23 to 40, completing the ear and hearing group and the entire vestibular group, at the same standard.