Clinical review

Acute otitis media

Paddy O'Neill, general practitioner. 

Norton Medical Centre, Stockton on Tees TS20 1AN

100674.3120{at}compuserve.com

This review of the effects of treatment for otitis media and of the effects of preventive interventions is one of over 60 chapters included in the first issue of Clinical Evidence, which is published by the BMJ Publishing Group. Future issues of Clinical Evidence will cover myringotomy; a separate chapter in issue 1 contains information on otitis media with effusion.

	Background

Top Background Option: Analgesia Option: Antibiotics Option: Short versus longer... Option: Long term antibiotic... References

Definition: Otitis media is inflammation in the middle ear. Subcategories include acute otitis media, otitis media with effusion (also known as "glue ear"), recurrent acute otitis media, and chronic suppurative otitis media. Acute otitis media presents with systemic and local signs and has a rapid onset. The persistence of an effusion beyond three months without signs of infection defines otitis media with effusion, whereas chronic suppurative otitis media is characterised by continuing inflammation in the middle ear giving rise to otorrhoea and a perforated tympanic membrane.

	Option: Analgesia

Top Background Option: Analgesia Option: Antibiotics Option: Short versus longer... Option: Long term antibiotic... References

We found limited evidence from one RCT that non-steroidal anti-inflammatory drugs are more effective than placebo in relieving pain.² The trial found no significant difference between paracetamol and placebo, but the dosing regimen may not have been optimal and the trial may have been too small.

Benefits
We found no systematic review. We found one double blind multicentre RCT comparing thrice daily treatment with ibuprofen, paracetamol, or placebo for 48 hours in 219 children aged 1-6 years with otoscopically proved acute otitis media.² All children received antibiotic treatment with ceflacor. The proportions of children still experiencing pain by the second day were 7% with non-steroidal anti-inflammatory drugs, 10% with paracetamol, and 25% with placebo. Ibuprofen was significantly more effective than placebo (P<0.01) but paracetamol was not (P value not given).There was no significant difference between placebo and active treatments for other outcomes (appearance of the tympanic membrane, rectal temperature, and parental assessment).

Harms
All treatments were equally well tolerated.

Comment
The trial may have been too small to detect a significant difference between paracetamol and placebo. The lack of significant difference may also be explained by the use of a three times daily regimen, since paracetamol is usually given four times daily. The evidence from this trial may be further limited because the assessment of the child's pain relief was based on parental observation, using a scale of 0 or 1.

	Option: Antibiotics

Top Background Option: Analgesia Option: Antibiotics Option: Short versus longer... Option: Long term antibiotic... References

Evidence from systematic reviews of RCTs is conflicting. The more recent and inclusive review suggests that antibiotics reduce the proportion of children still in pain at 2-7 days and reduce the risk of developing contralateral acute otitis media, but that they have no immediate beneficial effect in terms of reduced pain within 24 hours, and no long term effect in terms of rates of subsequent attacks or deafness at one month. Rates of adverse effects are almost doubled in children receiving antibiotics compared with placebo. There is no clear evidence favouring a particular antibiotic.

Benefits
Versus placebo or no treatment: We found two systematic reviews. The first identified four RCTs of antibiotics versus placebo or no treatment in 535 children aged 4 months to 18 years with acute otitis media.³ Co-intervention with analgesics and other means of relieving symptoms was allowed in most trials. Rate of treatment success (absence of all presenting symptoms and signs at around 7-14 days after treatment started) was significantly greater for active treatment (absolute risk 13.7% v 81%, absolute risk reduction 67.3%; no confidence interval given). This means that seven children would need to be treated with antibiotics for one additional child to achieve complete resolution of signs and symptoms, or that six of every seven children with acute otitis media either do not need or will not respond to antibiotic treatment (number needed to treat 7, no confidence interval given).

Harms
The first review gave no information on adverse events.³ In the second review, antibiotics were associated with a near doubling of the risk of vomiting, diarrhoea, or rashes (odds ratio 1.97; 1.19 to 3.25).⁴

Comment
The first review³ excluded two placebo controlled trials that were included in the second,⁴ on the basis that they included myringotomy as part of treatment. This may have biased results in favour of antibiotic treatment and may explain the lower number needed to treat given in the first review.

	Option: Short versus longer courses of antibiotics

Top Background Option: Analgesia Option: Antibiotics Option: Short versus longer... Option: Long term antibiotic... References

A systematic review of RCTs found increased risk of relapse or reinfection around 10 days but no difference in long term outcome with short courses (5 days) rather than longer courses of antibiotics.⁶

Benefits
We found one systematic review, which identified 32 RCTs of antibiotic treatment in children aged 4 weeks to 18 years with acute otitis media.⁶ Treatment failure, relapse, or reinfection at an early evaluation (8-19 days) were significantly more likely with shorter courses of antibiotics (5 days) than with longer courses (8-10 days) (summary odds ratio compared with longer courses 1.52; 1.17 to 1.98). However, by 20-30 days there were no significant differences between treatment groups (1.22, 0.98 to 1.54; absolute risk reduction 2.3%, 0.2% to 4.9%).

Harms
An RCT of amoxicillin plus clavulanate potassium in 868 children aged between 2 months and 12 years reported protocol defined diarrhoea in 26.7% of children receiving three times daily treatment for 10 days, compared with 9.6% in children receiving twice daily treatment for 10 days (P<0.0001), and 8.7% in children receiving twice daily treatment for five days (P<0.0001).⁷ No P value was quoted for the comparison between 10 day and 5 day twice daily treatments. The trial made no mention of other adverse effects such as rash.

Comment
The five day treatment group did not receive a placebo on days 6-10, which may have biased the results.    

	Option: Long term antibiotic treatment

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One systematic review of RCTs has found that long term antibiotic prophylaxis has a modest effect in preventing recurrences of acute otitis media.⁸ The questions of which antibiotic to use, for how long, and how many episodes of acute otitis media justify treatment have not yet been adequately evaluated.

Benefits
Versus placebo: We found one systematic review, which identified 33 RCTs comparing antibiotics versus placebo to prevent recurrent otitis media and otitis media with effusion.⁸ Nine of the trials (n=945) looked only at recurrent otitis media. It was not clear from the review which of the studies referred only to children; four either included the word "children" in the title or appeared in paediatric journals. Most studies defined recurrent otitis media as at least three episodes of acute otitis media in six months. The most commonly used antibiotics were amoxicillin, co-trimoxazole, and sulfamethoxazole, given for three months to two years. All nine studies showed a lower rate of recurrence with antibiotic treatment, although in seven the difference was not significant. Pooled results showed an absolute risk of 0.08 recurrences per patient per month for active treatment compared with 0.19 for placebo (absolute risk reduction 0.11 episodes per month; 0.03 to 0.19). This is a small effect favouring antibiotics, meaning that nine children with recurrent otitis media would need to be treated for a month to prevent one additional acute episode (number needed to treat 9, confidence interval not quoted).

Harms
No evidence was presented on the harmful effects of prophylactic treatment.

Comment
None.

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	Footnotes

      Competing interests: None declared.

	References

Top Background Option: Analgesia Option: Antibiotics Option: Short versus longer... Option: Long term antibiotic... References

1.	Froom J, Culpepper L, Jacobs M, DeMelker RA, Green LA, van Buchem L, et al. Antimicrobials for acute otitis media? A review from the International Primary Care Network. BMJ 1997; 315: 98-102[Free Full Text].
2.	Bertin L, Pons G, d'Athis P, Duhamel JF, Mandelonde C, Lasfargues G, et al. A randomized double blind multicentre controlled trial of ibuprofen versus acetaminophen and placebo for symptoms of acute otitis media in children. Fundam Clin Pharmacol 1996; 10: 387-392[Medline].
3.	Rosenfeld RM, Vertrees JE, Carr J, Cipolle RJ, Uden DL, Gieink GS, et al. Clinical efficacy of antimicrobial drugs for acute otitis media: meta-analysis of 5400 children from thirty-three randomised trials. J Pediatr 1994; 124: 355-367[Medline].
4.	Del Mar C, Glasziou P, Hayem M. Are antibiotics indicated as initial treatment for children with acute otitis media? A meta-analysis. BMJ 1997; 314: 1526-1529[Abstract/Free Full Text].
5.	Johansen HK, Gøtzschw PC, Osborne JE. Antibiotics as initial treatment for children with acute otitis media. BMJ 1997; 315: 879[Free Full Text].
6.	Kozyrskj AL, Hildes Ripstein E, Longstaffe SEA, Wincott JL, Sitar DS, Klassen TP, et al. Treatment of acute otitis media with a shortened course of antibiotics: a meta-analysis. JAMA 1998; 279: 1736-1742[Abstract/Free Full Text].
7.	Hoberman A, Paradise JL, Burch DJ, Valinski WA, Hedrick JA, Aronovitz GH, et al. Equivalent efficiency and reduced occurrence of diarrhoea from a new formulation of amoxycillin/clavulanate potassium (Augmentin) for treatment of acute otitis media in children. Pediatr Infect Dis J 1997; 16: 463-470[Medline].
8.	Williams RL, Chalmers TC, Stange KC, Chalmers FT, Bowin SJ. Use of antibiotics in preventing recurrent acute otitis media and in treating otitis media with effusion: a meta-analytic attempt to resolve the brouhaha. JAMA 1993; 270: 1344-1351[Abstract]. [Published erratum appears in JAMA 1994;271:430.]