Managing otitis media: an evidence-based approach

Otitis media is a common illness in young children. Historically it has been associated with frequent and severe complications. These days it is usually a mild condition that often resolves without treatment. This has led us to re-evaluate many interventions that were used routinely in the past. Evidence from a large number of randomised controlled trials can help in discussing treatment options with families. In Australia, Aboriginal children have more severe disease and will benefit from effective treatment of persistent (or recurrent) bacterial infection.

Otitis media is a common illness in young children (and occurs much less frequently in children over six years of age).^1,2In developed countries, otitis media is the commonest indication for antibiotic prescribing and surgery in young children. In the United States, annual costs were estimated to be US$3–5 billion in the 1990s.¹

Otitis media is best regarded as a spectrum of disease. The most important conditions are acute otitis media without perforation, acute otitis media with perforation, otitis media with effusion and chronic suppurative otitis media (see Table 1). There is currently a lack of consistency in definitions of different forms of otitis media (especially acute otitis media).

Children with middle ear infections will usually present with features related to:

• pain and/or fever (acute otitis media)
• hearing loss (otitis media with effusion)
• ear discharge (acute otitis media with perforation or chronic suppurative otitis media).

In some children, otitis media will be detected as part of a routine examination. Making an accurate diagnosis is not easy. Generally it requires a good view of the whole tympanic membrane and the use of either pneumatic otoscopy or tympanometry (to confirm the presence of a middle ear effusion). Studies of diagnostic accuracy in acute otitis media have found ear pain to be the most useful symptom, but not very reliable on its own. Bulging, opacity and immobility of the tympanic membrane are all highly predictive of acute otitis media. Normal (pearly grey) colour of the tympanic membrane makes acute otitis media unlikely.³

Acute otitis media

Most children will experience at least one episode of acute otitis media.1The peak incidence of infection occurs between 6 and 12 months. Although the pathogenesis of this condition is multi factorial, both viruses and bacteria are implicated.¹

The pain associated with acute otitis media resolves within 24 hours in around 60% and within three days in around 80% of patients.²Young children (under two years of age) are less likely to experience spontaneous resolution.⁴

Complications of acute otitis media include chronic suppurative otitis media, mastoiditis, labyrinthitis, facial palsy, meningitis, intracranial abscess, and lateral sinus thrombosis.⁵Mastoiditis was the most common life-threatening complication in the pre-antibiotic era. It is now rare in developed countries. A small proportion of children with acute otitis media will experience recurrent acute otitis media (three episodes in six months, or four episodes within 12 months).¹

This is the commonest form of otitis media and affects all children but is usually asymptomatic. The point prevalence in screening studies is around 20% in young children.¹It is more common in Aboriginal communities and was detected in over 40% of young children in a recent survey in the Northern Territory.⁶

Otitis media with effusion can occur spontaneously, as part of rhinosinusitis, or following an episode of acute otitis media. The same respiratory bacterial pathogens associated with acute otitis media have been implicated in its pathogenesis.

Most children will improve spontaneously within three months and complications from this illness are uncommon.¹A small proportion of children who have persistent otitis media with effusion have associated hearing loss. The average hearing loss associated with otitis media with effusion is around 25 decibels.¹Despite large numbers of studies, a causal relationship between otitis media with effusion and speech and language delay has not been proven.^5,7

Occasionally, children with acute otitis media with perforation will go on to develop chronic suppurative otitis media. In developed countries, chronic suppurative otitis media is now very uncommon and most often occurs as a complication of tympanostomy tube insertion. However, in impoverished populations including those in developed countries, chronic suppurative otitis media occurs as a complication of acute otitis media with perforation. In rural and remote communities in northern Australia, more than 20% of young children are affected.⁸

Chronic suppurative otitis media is the most disabling form of otitis media.^5,9Although there is a lack of well-designed longitudinal studies, this type of otitis media is most likely to persist without treatment.

The range of bacterial pathogens associated with chronic suppurative otitis media is considerably broader than that seen in acute otitis media. The associated hearing loss is usually more than that seen in otitis media with effusion. Chronic suppurative otitis media represents the most important cause of moderate conductive hearing loss (greater than 40 decibels) in many developing countries.⁹

A range of different interventions has been recommended for middle ear infections. Fortunately, many of these have been assessed in randomised controlled trials (see Table 2). This evidence can help with decision making, particularly when discussing options with families.

Acute otitis media

Most children with acute otitis media will improve spontaneously within 14 days and complications from this illness are uncommon. There are data from randomised controlled trials on antibiotics, antihistamines, decongestants, myringotomy and analgesics (see Table 2).²Antihistamines, decongestants and myringotomy showed no benefit.

The options at this stage are symptomatic relief with analgesics and either watchful waiting or antibiotics. Antibiotics are most appropriate in the following children:

• aged less than two years with bilateral acute otitis media
• with acute otitis media with perforation
• at risk of complications like chronic suppurative otitis media or mastoiditis (e.g. Aboriginal children living in remote communities, children with immunodeficiency syndromes)
• those who have already had 48 hours of watchful waiting.⁴

Aboriginal children in many communities have a relatively high risk of complications and so you would expect this group to be prescribed antibiotic treatment more often. Current national guidelines recommend amoxycillin 50 mg/kg/day in 2–3 daily doses.¹⁰

'Wait and see' prescribing

If the child is not in a high risk group but the family prefers antibiotic treatment, the clinician should discuss 'wait and see' prescribing. Provision of a script for an antibiotic along with advice only to use it if the pain persists for 48 hours will reduce antibiotic use by two-thirds (with no negative impact on family satisfaction).¹¹If antibiotics are to be used, there is evidence that a longer course of treatment (at least seven days) is more effective, but the beneficial effects are modest (persistent acute otitis media reduced from 22% to 15%). Amoxycillin is the most often prescribed antibiotic for this indication in Australia. Although some clinicians have strong preferences for other antibiotics, there is no evidence that any one of the commonly used antibiotics is more effective than the others.

Recurrent acute otitis media

Prophylactic antibiotics, adenoidectomy and tympanostomy tube insertion have been assessed in randomised controlled trials (Table 2).²Antibiotics given for 3–6 months are effective but the benefits are modest. A Cochrane review did not find any evidence that alternative antibiotics were more effective than amoxycillin.¹²The rates of acute otitis media also reduce spontaneously without treatment so that absolute benefits are less impressive than anticipated. Insertion of tympanostomy tubes also appears to reduce acute otitis media and the effect is similar to antibiotics. Either of these options could be considered in those children with very frequent severe infections (especially if occurring before the peak of respiratory illness in winter). However, children with tympanostomy tubes may develop a discharging ear, so this is not a good option in children at increased risk of suppurative infections (including those with immunodeficiency or persistent bacterial rhinosinusitis). For these children, prophylactic antibiotics or prompt antibiotic treatment of infections are probably the more appropriate choices. Consistent with this, the benefits of long-term antibiotics in reducing perforation of the tympanic membrane have been demonstrated in a randomised trial of Aboriginal infants living in a remote community.¹³In this study, infants with otitis media with effusion were randomised to twice-daily amoxycillin or placebo for up to six months. Episodes of acute otitis media continued to be treated with antibiotics, so benefits were presumably due to the fact that many episodes go unrecognised.

Otitis media with effusion

There is evidence from randomised controlled trials on treatment effects of antibiotics, insertion of tympanostomy tubes, autoinflation devices, antihistamines and decongestants, and antibiotics plus steroids (see Table 2).¹⁴

A course of watchful waiting may be appropriate initially. For those children who have persistent otitis media with effusion in both ears associated with hearing loss, a trial of antibiotics is reasonable. Insertion of tympanostomy tubes is most appropriate in children where the primary concern is the conductive hearing loss and communication difficulties. In randomised controlled trials of early versus late insertion of ventilation tubes, watchful waiting for 6–12 months did not adversely affect speech and language development. Children with the most severe conductive hearing loss or established speech and language problems are more likely to benefit.

Children who experience frequent suppurative infections (including those with immunodeficiency or persistent bacterial rhinosinusitis) are at greatest risk of developing chronic suppurative otitis media as a complication of tympanostomy tubes. Families should be informed that a small proportion of children will suffer recurrent persistent otitis media with effusion when the tympanostomy tubes are extruded, and may need a second operation. In these children, tympanostomy tubes plus adenoidectomy is a reasonable option.⁵

Chronic suppurative otitis media

Topical antibiotics, topical antiseptics, systemic antibiotics, and ear cleaning have been investigated in randomised clinical trials (see Table 2).⁹After a discussion with their doctor, most parents would choose topical antibiotic treatment initially. However, even though this is an effective treatment, prolonged or repeated courses of treatment are often required. If this is the case, topical quinolones will provide a slight benefit in terms of reduced risk of ototoxicity. Under the Pharmaceutical Benefits Scheme, ciprofloxacin ear drops are subsidised for Aboriginal and Torres Strait Islander people (aged one month or older).

Otitis media is a common illness that will usually resolve completely without specific treatment. Many interventions have been assessed in randomised controlled trials but none have had substantial absolute benefits for the populations studied. For most children, symptomatic relief and watchful waiting (including education of the parents about likely clinical course) is the most appropriate treatment option. Antibiotics have a role in children with (or at risk of) persistent bacterial infection and in children with discharge through a perforated tympanic membrane.