Otitis Media with Effusion

Fluid in the middle ear behind an intact tympanic membrane without signs or symptoms of acute infection. It is the commonest cause of acquired hearing loss in children, with a bimodal peak around 2 years and again at 5 years coinciding with school entry.

Pathophysiology

Eustachian tube dysfunction produces sustained negative middle ear pressure, transudation of fluid, and mucosal metaplasia with an increase in goblet cells and mucus producing glands. The effusion progresses from serous to mucoid, the glue ear of clinical usage.

Bacterial biofilms are demonstrable in a large proportion of effusions and explain both culture negativity and the failure of conventional antibiotic courses.

Adenoid tissue acts as a biofilm reservoir and a mechanical obstruction, which is why adenoidectomy contributes benefit independently of adenoid size.

Natural history, which governs management

• Approximately 50 percent of effusions resolve within 3 months.
• Roughly 95 percent resolve within 12 months.
• Effusion persisting beyond 3 months with documented hearing loss is the group in which intervention alters outcome.

Associations

Recent acute otitis media, upper respiratory infection, day care, passive smoking, allergic rhinitis, adenoid hypertrophy, cleft palate whether repaired or not, Down syndrome, primary ciliary dyskinesia, cystic fibrosis and immunodeficiency.

The critical adult rule

Unilateral otitis media with effusion in an adult is nasopharyngeal carcinoma until proven otherwise, particularly in patients of southern Chinese, Southeast Asian, North African and East African descent. Nasoendoscopy with biopsy of the fossa of Rosenmüller is mandatory. Do not insert a grommet and discharge such a patient.

• Hearing loss, typically a conductive loss averaging 25 to 30 dB, occasionally up to 40 dB. It fluctuates.
• In children, the presentation is often behavioural: inattention, turning up the television, mishearing, apparent disobedience, speech and language delay, poor school performance and frustration.
• Balance disturbance and clumsiness, which improve after treatment.
• Aural fullness and mild intermittent discomfort. Significant pain is not a feature and suggests an alternative diagnosis.
• No fever or systemic illness.

Otoscopic findings

• Dull, amber, straw coloured or greyish drum with loss of translucency.
• Retraction with a prominent lateral process of the malleus and foreshortened handle.
• Air fluid levels and bubbles, indicating partial aeration.
• Reduced mobility on pneumatic otoscopy, the most reliable bedside sign.
• Retraction pockets, atelectasis and adhesion to the promontory in long standing disease.

Findings that require action beyond routine management

• Deep attic or posterosuperior retraction pocket whose base cannot be seen.
• Keratin accumulation within a pocket, indicating early cholesteatoma.
• Severe atelectasis with ossicular erosion.
• Asymmetrical or unilateral effusion in an adult.

• Pneumatic otoscopy or microscopy, with wax removed first.
• Tympanometry: a type B trace with a normal ear canal volume confirms effusion. Type C with markedly negative pressure indicates tube dysfunction without frank effusion. In a child with a grommet or perforation, a type B trace with high canal volume indicates patency rather than effusion.
• Age appropriate audiometry: visual reinforcement audiometry from 6 months to 2.5 years, play audiometry from 2.5 to 4 years, and conventional pure tone audiometry thereafter, with bone conduction and masking to confirm the conductive nature.
• Otoacoustic emissions and auditory brainstem response where behavioural testing is unreliable.
• Two audiological assessments 3 months apart are required to establish persistence before surgery in most pathways.
• Speech and language assessment where delay is suspected.
• In adults: flexible nasoendoscopy in every case of unilateral effusion, with biopsy of any suspicious nasopharyngeal mucosa, plus magnetic resonance imaging where the index of suspicion is high.
• Consider immunological and ciliary investigation when effusion coexists with chronic rhinosinusitis, bronchiectasis or situs inversus.

Differential diagnosis

• Acute otitis media: pain, fever, bulging drum.
• Cholesteatoma: retraction pocket with keratin, foul discharge, focal erosion.
• Haemotympanum: blue drum after trauma or with cerebrospinal fluid leak.
• Glomus tympanicum: pulsatile red mass behind the drum with pulsatile tinnitus.
• Congenital sensorineural hearing loss coexisting with an effusion, which is why bone conduction must be tested.

Watchful waiting

• The default for at least 3 months from diagnosis in otherwise healthy children, given the high spontaneous resolution rate.
• Review with audiometry and tympanometry at 3 months.
• Advise on optimal listening conditions: face the child, reduce background noise, front seating in class, and inform the school.
• Eliminate tobacco smoke exposure and treat coexisting allergic rhinitis.

Autoinflation

• Nasal balloon autoinflation performed three times daily for several weeks improves middle ear aeration and is a reasonable, low cost measure for children over 3 to 4 years who can perform it. Benefit is modest and requires adherence.

Treatments without established benefit

• Prolonged or repeated antibiotic courses: transient effect only, with resistance and adverse effects. Not recommended.
• Antihistamines and decongestants: no benefit, with sedation and irritability.
• Intranasal corticosteroids: no meaningful benefit for the effusion itself, though they are appropriate where allergic rhinitis coexists.
• Oral corticosteroids: short term resolution that is not sustained, and unjustified adverse effects in children.
• Mucolytics: no consistent benefit.

Surgical management

Indications for ventilation tube insertion:

• Bilateral effusion persisting 3 months or longer with a hearing level of 25 to 30 dB HL or worse in the better hearing ear on two assessments 3 months apart.
• Lesser hearing loss where there is demonstrable impact on speech, language, learning, behaviour or balance.
• Structural damage: retraction pocket, atelectasis, ossicular erosion, or a pocket whose base cannot be inspected.
• Children with cleft palate or craniofacial anomalies, in whom spontaneous resolution is unlikely.
• Recurrent acute otitis media with persistent effusion between episodes.

Tube types and outcomes

• Short term tubes such as Shepard or Shah designs remain in place 6 to 12 months and extrude spontaneously. Hearing improves by approximately 10 to 12 dB, with the largest benefit in the first 6 to 9 months.
• T tubes remain longer and are chosen for repeated failures and craniofacial anomalies, but carry a persistent perforation rate of up to 16 percent compared with 2 to 5 percent for short term tubes.

Adenoidectomy

• Added to tube insertion in children over 4 years, in children requiring repeat insertion, and where there is nasal obstruction, chronic rhinosinusitis or obstructive symptoms.
• Reduces the need for further surgery irrespective of adenoid size.
• Avoid in overt or submucous cleft palate and where there is a bifid uvula or velopharyngeal insufficiency risk, because of hypernasality.

Hearing aids

• A valid alternative when surgery is declined, when anaesthesia carries excess risk, and as the preferred first option in many children with Down syndrome, whose narrow canals, higher rates of persistent otorrhoea and anaesthetic risks make tubes less attractive.

Postoperative care and complications

• Routine water precautions are not required for ordinary bathing and surface swimming. Advise against deep diving and against submerging in soapy bathwater, which reduces surface tension.
• Post insertion otorrhoea occurs in 10 to 25 percent. Treat with ciprofloxacin 0.3 percent with dexamethasone 0.1 percent drops, 4 drops twice daily for 7 days, in preference to oral antibiotics, together with aural toilet.
• Blockage, premature extrusion and granulation at the tube.
• Retained tube beyond 2 to 3 years should be removed, since persistent perforation risk rises.
• Persistent perforation after extrusion in 2 to 5 percent with short term tubes.
• Tympanosclerosis in 30 to 40 percent, generally without functional consequence.
• Segmental atrophy and retraction at the insertion site.
• Cholesteatoma in well under 1 percent.

Follow up

• Review at 6 to 8 weeks with otoscopy and audiometry, then 6 monthly until the tube extrudes and the ear is confirmed aerated and hearing normal.
• Continue surveillance in children with cleft palate and Down syndrome into adolescence.
• Any child with persisting hearing loss after resolution of the effusion requires full audiological reassessment for a sensorineural component.