Describe chronic suppurative otitis media of the tubotympanic type.

Nature and Pathology

• Chronic suppurative otitis media (CSOM) is a long-standing infection of the middle ear cleft with a permanent perforation of the tympanic membrane.
• The tubotympanic (mucosal, "safe") type involves the anteroinferior part of the cleft and the Eustachian tube, and does not produce cholesteatoma.
• CSOM remains a major cause of preventable hearing loss and of death from intracranial sepsis in India, and is far commoner here than in high-income countries because of overcrowding, poor nutrition, untreated upper respiratory infection and limited access to care

Clinical Features and Management

• The two cardinal symptoms are discharge and deafness:
• Discharge (otorrhoea) that is profuse, mucoid or mucopurulent, odourless and non-blood-stained, and characteristically intermittent — worsening with upper respiratory infection or water entry and settling between. The mucoid character is the point: mucus can only come from middle ear mucosa, so it indicates mucosal rather than bony disease
• Deafness — conductive, mild to moderate (20 to 40 dB), and depending on the size and site of the perforation and the state of the ossicles. A loss exceeding 40 to 50 dB suggests ossicular involvement
• Paradoxically, some patients hear better when the ear is discharging — the "round window shielding" effect, in which fluid bridges an ossicular gap and restores some conduction. Its presence suggests ossicular discontinuity
• Pain, vertigo, facial weakness or headache are not features of safe disease, and their appearance means either an acute exacerbation, otitis externa, or a complication — and should always prompt reassessment
• Examination — a central perforation with pale, healthy or oedematous middle ear mucosa visible through it; mucoid discharge; and NO attic involvement, NO granulations, NO cholesteatoma. The attic must be inspected specifically.
• Tuning fork tests and pure tone audiometry confirm a conductive loss; a sensorineural component may develop with long-standing disease from toxin diffusion through the round window
• Swab for culture and sensitivity; and examine the nose, throat and postnasal space.
• Medical treatment — the aim is to obtain a dry ear:
• Aural toilet is the single most important measure, by dry mopping or suction under vision, repeated as often as necessary. Drops cannot work in an ear full of discharge
• Topical antibiotic drops — ciprofloxacin or ofloxacin are preferred because they are not ototoxic. Aminoglycoside drops (neomycin, gentamicin) should be avoided or used only briefly in the presence of a perforation.
• Systemic antibiotics for acute exacerbations, guided by culture
• Keep the ear dry — no swimming, cotton wool and petroleum jelly while bathing. This instruction does more than any drop
• Treat the nose and throat — allergic rhinitis, sinusitis, adenoids and tonsils.
• Surgical treatment — myringoplasty or tympanoplasty once the ear has been dry for at least 6 weeks to 3 months, to close the perforation, restore hearing and prevent reinfection; with ossicular reconstruction where needed. Cortical mastoidectomy is added where there is persistent discharge from mastoid disease
• Safe does not mean harmless; tubotympanic disease still causes significant deafness and can complicate during an exacerbation
• Mucus can only come from middle ear mucosa, so mucoid discharge indicates mucosal rather than bony disease
• A central perforation has a rim all round, so the annulus is intact, which is the definition rather than a description of position
• Pain, vertigo or facial weakness are not features of safe disease, and their appearance demands reassessment
• Better hearing when discharging suggests ossicular discontinuity, the fluid bridging the gap and restoring some conduction
• A loss beyond forty to fifty decibels suggests ossicular damage rather than the perforation alone
• Use ciprofloxacin or ofloxacin drops, which are not ototoxic, rather than aminoglycosides through a perforation
• Aminoglycoside drops risk sensorineural loss when the drum is perforated, and should be avoided or used only briefly
• Aural toilet does more than any drop, and must be repeated as often as the discharge recurs