Fluid in the Middle Ear and Glue Ear

Synonyms: otitis media with effusion (OME).

Glue ear is defined as inflammation of the middle ear, accompanied by the accumulation of fluid in the middle-ear cleft, without the symptoms and signs of acute inflammation.¹
It often results in conductive hearing loss, and is the commonest cause of hearing loss and elective surgery in childhood. In ears with documented fluid, the average hearing loss is 20 decibels (dB), but may be as high as 50 dB.

Glue ear is the commonest cause of acquired hearing loss in childhood.

• Incidence in young children is high, with most having at least one episode of glue ear during early childhood.
• Prevalence is significantly lower than incidence, owing to the short duration of episodes of glue ear. There is a peak of 20% at 2 years of age, with a second peak in the sixth year.²

Studies have varied in their findings, owing to different case mixes, sample sizes, and definitions of glue ear:

• In one study 856 children aged 5-8 years were followed until they left primary school.³
• At least one episode of glue ear occurred in 27% of children.
• The annual incidence was 27% for children aged 5 years, which dropped to 7% for children aged 8 years.

Risk factors

More common in:

• Boys than girls
• Children in day-care
• Children with older siblings
• Parents who smoke
• During winter
• Recurrent upper respiratory tract infections²

In a small proportion these persist over months or years.

The following symptoms may be noted:

• Earache (not always present)
• Hearing loss and/or behavioural problems
• Hearing loss may be significant (20-30db) - particularly if it occurs in both ears and has persisted for >1 month
• Can occur without hearing loss

Otosocopy may be useful, although a normal-looking eardrum does not exclude glue ear. One or more of the following signs may be seen if glue ear is present:

• Opacification of the drum (other than due to scarring)
• Loss of the light reflex, or a more diffused light reflex
• Indrawn, retracted, or concave drum
• Decreased or absent mobility of the drum
• Presence of bubbles or fluid level
• Yellow or amber colour change to the drum
• Fullness or bulging of the drum, though this is not typical

Pneumatic otoscopy assesses eardrum mobility. Its use increases the sensitivity of diagnosing glue ear, but it is not widely available in primary care in the UK.

When to refer a child for formal hearing assessment varies according to the presentation:

• If the hearing loss has lasted for more than a month, referral is usually appropriate.
• If the history is shorter than this, the parents should be advised to bring their child back if the problem seems to be persisting for more than a month, so that a hearing test can be arranged.

Hearing assessment

• Pure-tone audiometry is the best way to assess hearing.
  • However, this is only suitable for children who are 4 years and older.
  • Children younger than this are not usually able to co-operate.
• The McCormick Toy Test and the Distraction tests are suitable for children younger than 4 years.
  • These tests do not provide a quantitative level of loss.
  • A hearing loss of 25 decibels (dB) or greater in the better ear is usually important.
  • With a hearing loss of 30 dB, normal conversation may sound like a soft whisper.¹

General advice

• Give written information about glue ear to the parents.
• Advise parents or carers not to expose the child to tobacco smoke.

Certain groups of children with persistent glue ear and the predominant symptom of deafness, can use a hearing aid as an effective treatment for their deafness with high acceptance and compliance, during the temporary (for the most) loss.⁴ The stigma of an aid has been reported as minimal under the age of seven.⁵ Long-term effects of using aids still need to be evaluated.

Referral

• Children under 4 years old with glue ear should be referred to an ENT specialist.⁶
• Children who are 4 years and older and present with glue ear can be safely managed with watchful waiting, repeat audiometry being performed in 3 months.
• Watchful waiting is not appropriate for children who have significant disability or who have associated high-risk conditions e.g. Down's syndrome, cleft palate.
• Children who are 4 years and older with persistent glue ear who have problems with speech and language, behaviour or development should also be referred.

Drugs

Medical management is not recommended.⁷

Surgical

The benefits of surgery have to be balanced against possible harms. There are also the slight risks of general anaesthesia and the psychological trauma of hospitalisation and operation.²Treatment options are grommet insertion, adenoidectomy, or both:

• Adenoidectomy with grommet insertion seems to provide more prolonged improvement than either alone.⁸
  • Surgery may resolve glue ear and improve hearing in the short term, but there is less certainty about long-term outcomes.²
  • There is large variation in effect between children.
  • There is a slight risk of haemorrhage after adenoidectomy.
• The use of grommets is common, but controversial:
  • The insertion of grommets, alone or with adenoidectomy, has minimal effect.^9,10
  • All guidelines recommend that watchful waiting combined with audiometry to exclude more serious hearing loss may be more appropriate.^1,6,7
  • Tympanosclerosis frequently occurs after grommet insertion, although the long-term consequences of this are uncertain.
  • Infection after grommet insertion may occur, and there is also a slightly increased incidence of chronic perforation.
• Autoinflation may be of benefit in older, motivated children:¹¹
  • However, the trial data are poor quality.
  • The recommended method is with an otovent device.
  • A balloon is inflated by blowing into it from one nostril, while sealing the other nostril with a finger.
  • This action results in an increase in intranasal pressure and opening of the Eustachian tube (i.e. a Valsalva manoeuvre).

There is also debate about how to select children for surgery. The issue is complicated by the high rate of resolution of glue ear, particularly in younger children.^12,13
Timing of surgery may not be critical.

In adults

Glue ear is unusual in adults and the aim of management should be to determine the underlying cause.
There is little evidence on treatment options and complications in adults.⁷

• Adults with unilateral glue ear should be referred to the Ear, Nose, and Throat department to exclude a nasopharyngeal carcinoma.
• Adults with bilateral glue ear should be referred to exclude nasal polyps.

Glue ear may adversely affect speech, language development, behaviour, and education.
However, the evidence shows only a weak association between glue ear and delayed speech and language development.¹⁴ Most studies suggest any adverse effect is temporary in the majority of children.¹

Spontaneous resolution of glue ear is common in community cohort studies:

• 50% resolve within 3 months and 95% within a year.¹³
• In most children, problems with glue ear do not persist beyond early childhood.