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BMJ Clin Evid. 2008; 2008: 0510.
Published online 2008 June 26.
PMCID: PMC2907945

Otitis externa

Daniel Hajioff, Consultant ENT Surgeon# and Samuel MacKeith, ENT Registrar#

Abstract

Introduction

Otitis externa is thought to affect 10% of people at some stage, and can present in acute, chronic, or necrotising forms. Otitis externa may be associated with eczema of the ear canal, and is more common in swimmers, humid environments, people with absence of ear wax or with narrow ear canals, hearing-aid users, and after mechanical trauma.

Methods and outcomes

We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of empirical and prophylactic treatments for otitis externa? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

Results

We found nine systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

Conclusions

In this systematic review we present information relating to the effectiveness and safety of the following interventions: oral antibiotics, specialist aural toilet, topical acetic acid drops or spray, topical aluminium acetate drops, topical antibacterials, topical antifungals, topical anti-infective agents, topical corticosteroids, and water exclusion.

Key Points

Otitis externa is thought to affect 10% of people at some stage, and can present as acute, chronic, or necrotising forms.

  • Otitis externa may be associated with eczema of the ear canal, and is more common in swimmers, humid environments, people with absence of ear wax or narrow ear canals, hearing-aid users, and after mechanical trauma.
  • The most common pathogens are Pseudomonas aeruginosa and Staphylococcus aureus.
  • Fungal overgrowth can occur, especially after prolonged antibiotic use.

Topical antibacterial agents are likely to improve signs and symptoms of otitis externa.

  • Combining topical antibacterial agents and corticosteroids (methylprednisolone-neomycin drops) is likely to be more effective than placebo in reducing signs and symptoms of otitis externa over 28 days.
  • We don't know whether any one topical antibacterial regimen should be used in preference to another.

Consensus suggests thatTopical corticosteroids alone may reduce signs and symptoms of otitis externa but few good-quality studies have been found assessing these agents alone in this population.

We don't know whether topical antifungal agents or specialist aural toilet improve symptoms of otitis externa.

Oral antibiotics have not been shown to be beneficial.

  • Consensus suggests that adding oral antibiotics to topical anti-infective agents will not improve symptoms compared with topical agents alone.

Topical acetic acid is likely to increase cure of otitis media when used with topical anti-infective agents and corticosteroids, but is less effective when used alone.

Prophylactic treatments to prevent otitis externa (topical acetic acid, topical corticosteroids, and water exclusion) have not been evaluated in clinical trials.

About this condition

Definition

Otitis externa is inflammation of the external ear canal, often with infection. This inflammation is usually generalised throughout the ear canal, so is often referred to as "diffuse otitis externa". This review excludes localised inflammations, such as furuncles. Otitis externa has acute (less than 6 weeks), chronic (more than 3 months), and necrotising (malignant) forms. Acute otitis externa may present as a single episode, or may recur. It causes pain with aural discharge and associated hearing loss. If the ear canal is visible, it appears red and inflamed. Pseudomonas aeruginosa and Staphylococcus aureus are the most frequent bacterial pathogens in otitis externa. Fungal overgrowth (e.g. with Aspergillus niger) is also common, especially after prolonged antibiotic treatment. Chronic otitis externa may result in canal stenosis with associated hearing loss, for which it may be difficult to fit hearing aids. Necrotising otitis externa is defined by destruction of the temporal bone, usually in people with diabetes or in people who are immunocompromised, and can be life threatening. In this review, we look at the empirical treatment of only acute and chronic otitis externa.

Incidence/ Prevalence

Otitis externa is common worldwide. The exact incidence is unknown, but 10% of people are thought to have been affected at some time. The condition does affect children, but is more common in adults. It accounts for a large proportion of the workload in otolaryngology departments, but milder cases are often managed in primary care.

Aetiology/ Risk factors

Otitis externa may be associated with local or generalised eczema of the ear canal. It is more common in swimmers, humid environments, people with an absence of ear wax or narrow external ear canals, hearing-aid users, and after mechanical trauma.

Prognosis

We found few reliable data. Many cases of otitis externa resolve spontaneously over several weeks or months. Acute episodes tend to recur, although risk of recurrence is unknown. Experience suggests that chronic inflammation affects a small proportion of people after a single episode of acute otitis externa, and can, rarely, lead to canal stenosis.

Aims of intervention

To improve or abolish symptoms; to prevent recurrence and complications, with minimal adverse effects.

Outcomes

Severity and duration of signs and symptoms (pain, discharge, hearing loss, redness); rates of resolution or cure (defined as complete resolution of signs and symptoms); prevention of recurrence; ability to use hearing aids; quality of life; adverse effects of treatment.

Methods

BMJ Clinical Evidence search and appraisal October 2007. The following databases were used to identify studies for this review: Medline 1966 to October 2007, Embase 1980 to October 2007, and The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials 2007, Issue 3. Additional searches were carried out using these websites: NHS Centre for Reviews and Dissemination (CRD) — for Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA), Turning Research into Practice (TRIP), and NICE. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the author for additional assessment, using predetermined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews and RCTs in any language, at least single blinded, and containing more than 20 individuals of whom more than 80% were followed up. The minimum length of follow-up required to include studies was one month. We excluded all studies described as "open", "open label", or not blinded unless blinding was impossible. In addition, we use a regular surveillance protocol to capture harms alerts from organisations, such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA), which are added to the review as required. We performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table ).

Table
GRADE evaluation of interventions for otitis externa

Glossary

Aural toilet
Aural toilet is usually performed in a secondary (specialist) setting and includes dry mopping of the ear canal or suction. These can be performed using a head light or microscope, which allows cleaning of the more medial areas of the ear canal.
High-quality evidence
Further research is very unlikely to change our confidence in the estimate of effect.
Low-quality evidence
Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Moderate-quality evidence
Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Very low-quality evidence
Any estimate of effect is very uncertain.

Notes

Disclaimer

The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients.To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.

Contributor Information

Daniel Hajioff, Southmead Hospital, Bristol Royal Hospital for Children, Bristol, UK.

Samuel MacKeith, Southmead Hospital, Bristol, UK.

References

1. Agius AM, Pickles JM, Burch KL. A prospective study of otitis externa. Clin Otolaryngol 1992;17:150–154. [PubMed]
2. Doroghazi RM, Nadol JB, Hyslop NE, et al. Invasive external otitis. Report of 21 cases and review of the literature. Am J Med 1981;71:603–618. [PubMed]
3. Raza SA, Denholm SW, Wong JC. An audit of the management of otitis externa in an ENT casualty clinic. J Laryngol Otol 1995;109:130–133. [PubMed]
4. Hirsch BE. Infections of the external ear. Am J Otolaryngol 1992;13:145–155. [PubMed]
5. Lambert IJ. A comparison of the treatment of otitis externa with (“Otosporin”) and aluminium acetate: a report from a services practice in Cyprus. J R Coll Gen Pract 1981;31:291–294. [PMC free article] [PubMed]
6. Cannon SJ, Grunwaldt E. Treatment of otitis externa with a tropical steroid–antibiotic combination. Eye Ear Nose Throat Mon 1967;46:1296–1302. [PubMed]
7. Rosenfeld RM, Singer M, Wasserman JM, et al. Systematic review of topical antimicrobial therapy for acute otitis externa. Otolaryngol Head Neck Surg 2006;134:S24–S48. [PubMed]
8. Jones RN, Milazzo J, Seidlin M. Ofloxacin otic solution for treatment of otitis externa in children and adults. Arch Otolaryngol Head Neck Surg 1997;123:1193–1200. [PubMed]
9. Worgan D. Treatment of otitis externa. Report of a clinical trial. Practitioner 1969;202:817–820. [PubMed]
10. Smith RB, Moodie J. A general practice study to compare the efficacy and tolerability of a spray (“Otomize”) versus a standard drop formulation (“Sofradex”) in the treatment of patients with otitis externa. Curr Med Res Opin 1990;12:12–18. [PubMed]
11. Johnston MN, Flook EP, Mehta D, et al. Prospective randomised single-blind controlled trial of glacial acetic acid versus glacial acetic acid, neomycin sulphate and dexamethasone spray in otitis externa and infected mastoid cavities. Clin Otolaryngol 2006;31:504–507. [PubMed]
12. Jacobsson S, Karlsson G, Rigner P, et al. Clinical efficacy of budesonide in the treatment of eczematous external otitis. Eur Arch Otorhinolaryngol 1991;248:246–249. [PubMed]
13. van Balen FAM, Smit, WM, Zuithoff NPA, et al. Clinical efficacy of three common treatments in acute otitis externa in primary care: randomized control trial. BMJ 2003;327:1201–1203 [PMC free article] [PubMed]
14. Yelland MJ. The efficacy of oral cotrimoxazole in the treatment of otitis externa in general practice. Med J Aust 1993;158:697–699. [PubMed]
15. Pond F, McCarty D, O'Leary S. Randomized trial on the treatment of oedematous acute otitis externa using ear wicks or ribbon gauze: clinical outcome and cost. J Laryngol Otol 2002;116:415–419. [PubMed]
2008; 2008: 0510.
Published online 2008 June 26.

Aluminium acetate (topical) for treating otitis externa

Summary

CURE RATES Topical aluminum acetate compared with topical antibacterial–corticosteroid: Aluminium acetate drops are no more effective at increasing cure rates at 4 weeks in people with acute diffuse otitis externa ( moderate-quality evidence ). NOTE We found no direct information about whether topical aluminium acetate is better than no active treatment.

Benefits

We found no systematic review.

Aluminium acetate drops versus placebo:

We found no RCTs.

Aluminium acetate drops versus topical antibacterials alone, versus topical antifungals, versus topical corticosteroids alone, versus topical acetic acid, or versus oral antibiotics:

We found no RCTs.

Aluminium acetate drops versus topical antibacterial–corticosteroid:

One RCT (126 people with any severity of acute diffuse otitis externa on otoscopy) compared aluminium acetate drops versus polymyxin–neomycin–hydrocortisone drops in a primary-care setting for 14 days. If present, people in both groups had discharge removed (no further details of technique provided). The RCT found no significant difference between groups in clinical cure rate at 4 weeks, or mean time to clinical resolution (clinical cure rate: 59/65 [91%] with aluminium acetate v 49/61 [80%] with polymyxin–neomycin–hydrocortisone, P greater than 0.2; mean time to clinical resolution: 9.4 days with aluminium acetate v 11.1 days with polymyxin–neomycin–hydrocortisone, P greater than 0.2).

Harms

Aluminium acetate drops versus placebo:

We found no RCTs.

Aluminium acetate drops versus topical antibacterials alone, versus topical antifungals, versus topical corticosteroids alone, versus topical acetic acid, or versus oral antibiotics:

We found no RCTs.

Aluminium acetate drops versus topical antibacterial-corticosteroid:

The RCT gave no information on adverse effects.

Comment

Although we have not identified an RCT comparing topical aluminium acetate versus no active treatment, the cure rates reported in the included RCT suggest that topical aluminium acetate is likely to be beneficial. The RCT may be underpowered to identify a clinically important difference in efficacy between the two treatments used.

Clinical guide:

Topical aluminium acetate is often used for the treatment of fungal otitis externa, or as a prophylactic treatment of recurrent otitis externa. However, there is little evidence to confirm these beneficial effects.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Antibacterials (topical; with or without corticosteroids)

Summary

SYMPTOM IMPROVEMENT Topical antibacterial–corticosteroid compared with placebo: Topical antibacterial–corticosteroid (methylprednisolone–neomycin drops) is more effective at improving symptoms of otitis externa at 28 days ( moderate-quality evidence ). Topical antibacterial–corticosteroid–acetic acid compared with topical antibacterial–corticosteroid: Neomycin–dexamethasone–acetic acid spray is more effective than framycetin–gramicidin–dexamethasone drops at improving signs and symptoms of severe acute or chronic diffuse otitis externa at 1 month (moderate-quality evidence). CURE RATES Topical antibacterials (with or without corticosteroid) compared with each other: We don't know which antibiotic is more effective at improving clinical cure rates ( very low-quality evidence ). Topical antibacterial–corticosteroid compared with topical aluminium acetate: Topical antibacterial–corticosteroid and topical aluminium acetate are equally effective at increasing cure rates at 4 weeks in people with acute diffuse otitis externa (moderate-quality evidence). Topical antibacterial–corticosteroid compared with topical acetic acid: Topical antibacterial–corticosteroid is more effective at improving cure rates at 21 days in people with diffuse acute otitis externa ( high-quality evidence ). Topical antibacterial–corticosteroid–acetic acid compared with topical acetic acid alone: Neomycin–dexamethasone–glacial acetic acid spray is more effective at increasing the proportion of people with inactive disease at 4 weeks (moderate-quality evidence). RECURRENCE Topical antibacterial–corticosteroid compared with topical acetic acid: Antibacterial–corticosteroid is more effective at reducing the risk of recurrence at 21–48 days in people with diffuse acute otitis externa (high-quality evidence). NOTE We found no clinically important results about topical antibacterials compared with no active treatment in people with otitis externa.

Benefits

We found no systematic review.

Topical antibacterials alone versus placebo:

We found no RCTs.

Topical antibacterials alone versus topical aluminium acetate:

We found no RCTs.

Topical antibacterials alone versus topical antifungals:

We found no RCTs.

Topical antibacterials alone versus topical corticosteroids:

We found no RCTs.

Topical antibacterials alone versus oral antibiotics:

We found no RCTs.

Adding oral antibiotics to topical antibacterials:

See benefits of oral antibiotics.

Topical antibacterial–corticosteroids versus placebo:

One double-blind RCT (40 people in secondary care with mild, moderate, or severe acute/chronic diffuse otitis externa) compared methylprednisolone–neomycin drops versus placebo drops for 10 days. All people in the RCT had “cleansing” of their external ear canals (details not reported). The RCT found that methylprednisolone–neomycin drops significantly improved symptoms and signs compared with placebo at 28 days (“good” response: 11/20 [55%] with methylprednisolone–neomycin drops v 2/20 [10%] with placebo; P less than 0.001).

Topical antibacterial–corticosteroids versus topical aluminium acetate:

See benefits of topical aluminium acetate.

Topical antibacterials (with or without corticosteroids) versus each other:

We found one systematic review (search date 2005) on topical antimicrobial therapy for the treatment of acute otitis externa. We found two additional RCTs comparing different regimens of topical antibacterials. The review carried out a meta-analysis for topical quinolone antibiotics versus topical non-quinolone antibiotics (3 RCTs, 936 people). It found no significant difference between topical quinolone and topical non-quinolone antibiotics in clinical cure rate at 14–28 days (see table 1 ). However, only one RCT included in the meta-analysis compared topical quinolone alone versus topical non-quinolone alone, which may affect the generalisability of these results. One RCT compared topical quinolone alone versus topical quinolone plus corticosteroid versus topical non-quinolone plus corticosteroid, and one RCT compared topical quinolone plus corticosteroid versus topical non-quinolone plus corticosteroid. Ciprofloxacin was the quinolone antibiotic used in all studies included in the meta-analysis, either alone or in combination with hydrocortisone.The non-quinolone antibiotics investigated were tetramycin and neomycin–polymyxin combination. Pooling data from different groups may fail to demonstrate true significant differences, which would be identified if specific combinations were compared separately. The first additional RCT (single blind, 601 people with any severity of acute diffuse otitis externa on otoscopy) compared ofloxacin drops versus neomycin–hydrocortisone–polymyxin B drops in a primary-care setting for 10 days. At 1 month, it found no significant difference between groups for clinical or microbiological cure rate (see table 1 ). The second RCT (double blind, 55 people with moderate–severe acute or chronic diffuse otitis externa on otoscopy, in a secondary-care setting) compared drops containing hydrocortisone–neomycin sulphate–polymyxin B versus drops containing triamcinolone–neomycin undecenoate for 1 month or until resolution of all symptoms and signs. All people received microsuction if discharge was present. The RCT found that triamcinolone–neomycin drops significantly improved resolution rates compared with hydrocortisone–neomycin–polymyxin B drops at 1 month (see table 1 ).

Table 1
Topical antibacterials versus each other

Topical antibacterial–corticosteroid versus topical acetic acid:

See benefits of topical acetic acid.

Topical antibacterial–corticosteroid–acetic acid versus topical antibacterial–corticosteroid alone:

We found one RCT. One single-blind RCT (60 people with any severity of acute or chronic diffuse otitis externa on otoscopy) compared neomycin–dexamethasone–acetic acid spray versus framycetin–gramicidin–dexamethasone drops in a primary-care setting for 10 days. At 1 month, the neomycin–dexamethasone–acetic acid spray significantly improved symptoms and signs compared with the framycetin–gramicidin–dexamethasone drops (see table 2 ).

Table 2
Topical antibiotic–corticosteroid–acetic acid versus topical antibiotic–corticosteroid

Topical antibacterial–corticosteroid– acetic acid versus topical acetic acid alone:

We found one single-blind RCT (109 people with acute otitis externa or an infected mastoid cavity) which compared neomycin (3250 U/mL)–dexamethasone (0.1%)–glacial acetic acid (2%) spray versus glacial acetic acid (2%) spray alone. All people included in the study received aural toilet before randomisation to treatment. The RCT carried out a subgroup analysis of people with acute otitis externa (53 people in secondary care with acute otitis externa on otoscopy). People were assessed for inactive disease at 2 and 4 weeks' follow-up. At 4 weeks, the RCT found that a significantly larger proportion of people had inactive disease after treatment with neomycin–dexamethasone–glacial acetic acid compared with glacial acetic acid alone (18/21 [86%] with neomycin–dexamethasone–glacial acetic acid v 12/32 [38%] with glacial acetic acid alone; P less than 0.0005). At 2 weeks' follow-up, people with no sign of active disease were instructed to discontinue use of their spray. Those with active disease underwent additional aural toilet and continued with their assigned treatment for a further 2 weeks. The RCT carried out an ITT analysis (assigned explicit allocation of poor outcome to those not completing the protocol).

Harms

Topical antibacterials alone versus placebo:

We found no RCTs.

Topical antibacterials alone versus topical aluminium acetate:

We found no RCTs.

Topical antibacterials alone versus topical antifungals:

We found no RCTs.

Topical antibacterials alone versus topical corticosteroids:

We found no RCTs.

Topical antibacterials alone versus oral antibiotics:

We found no RCTs.

Adding oral antibiotics to topical antibacterials:

See harms of oral antibiotics.

Topical antibacterial–corticosteroids versus placebo:

The RCT gave no information on adverse effects.

Topical antibacterials (with or without corticosteroids) versus each other:

The systematic review carried out a meta-analysis of RCTs reporting adverse effects (3 RCTs, 1330 people) for the comparison of topical quinolone versus topical non-quinolone antibiotics. The review found no significant difference in rates of adverse effects between topical quinolones and topical non-quinolones (see table 1 ). No further information was given on the adverse effects reported. The first additional RCT found no significant difference in adverse events between treatments; headache, ear pain, pruritus, dizziness, and vertigo were most commonly reported (see table 1 ). The second RCT gave no information on adverse effects.

Topical antibacterial–corticosteroid–acetic acid versus topical antibacterial–corticosteroid:

The first RCT reported similar rates of local stinging or burning in the first few days of treatment with neomycin–dexamethasone–acetic spray versus framycetin–gramicidin–dexamethasone drops. see table 2 .

Topical antibacterial–corticosteroid versus topical acetic acid:

See harms of topical acetic acid.

Topical antibacterial–corticosteroid–acetic acid versus topical acetic acid:

The RCT gave no information on adverse effects.

Comment

None.

Substantive changes

Topical antibacterials (with or without corticosteroids): One systematic review and one additional RCT added; benefits and harms data enhanced; categorisation unchanged (Likely to be beneficial). The review found no significant difference between topical quinolone antibiotics and topical non-quinolone antibiotics in clinical cure rate at 14–28 days. However, the analysis included some RCTs comparing quinolone antibiotics and non-quinolone antibiotics in combination with corticosteroids, which may affect the generalisability of the results. The additional RCT found that a larger proportion of people had inactive disease at 4 weeks after treatment with neomycin–dexamethasone–glacial acetic acid compared with glacial acetic acid alone.

2008; 2008: 0510.
Published online 2008 June 26.

Antifungals (topical; with or without corticosteroids)

Summary

We found no direct information about whether topical antifungals are more effective than no active treatment in people with otitis externa. We found no clinically important results about topical antifungals (alone or in combination with other anti-infective agents or corticosteroids) compared with oral antibiotics, topical corticosteroids, topical aluminium acetate drops, topical acetic acid, or other topical anti-infective agents in people with otitis externa.

Benefits

We found no systematic review. We found no RCTs comparing topical antifungals (with or without corticosteroids, or in combination with oral antibiotics) versus placebo, topical aluminium acetate, topical antibacterials, topical corticosteroids, topical acetic acid, or oral antibiotics in people with otitis externa.

Harms

We found no RCTs.

Comment

Clinical guide:

There is little evidence assessing the use of topical antifungal agents in acute otitis externa. Fungal otitis externa may be suspected by otoscopic examination findings of hyphae or spores (e.g. Aspergillus niger), or by swab cultures. People with fungal otitis externa have often had previous prolonged courses of a combination of corticosteroid plus antibiotic agents. In this group of people, it may be appropriate to use topical antifungal agents or other antiseptic agents, such as aluminium acetate or acetic acid. Antiseptic agents have the advantage that they are not ototoxic or allergenic, meaning they are probably safer, particularly in the long term. However, anecdotal evidence suggests they may cause more discomfort, which may lead to poor compliance and resultant poor efficacy.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Corticosteroids (topical) for treating otitis externa

Summary

SYMPTOM IMPROVEMENT Topical corticosteroid–antibacterial compared with placebo: Topical corticosteroid–antibacterial (methylprednisolone–neomycin drops) is more effective at improving symptoms of otitis externa at 28 days ( moderate-quality evidence ). Topical corticosteroid–antibacterial–acetic acid spray compared with topical corticosteroid–antibacterial:: Neomycin–dexamethasone–acetic acid spray is more effective than framycetin–gramicidin–dexamethasone drops at improving signs and symptoms of severe acute or chronic diffuse otitis externa at 1 month (moderate-quality evidence). CURE RATES Topical corticosteroid–antibacterial compared with topical aluminium acetate: Topical corticosteroid–antibacterial and topical aluminum acetate seem to be equally effective at increasing cure rates at 4 weeks in people with acute diffuse otitis externa (moderate-quality evidence). Topical corticosteroid–antibacterial compared with topical acetic acid: Topical corticosteroid–antibacterial is more effective at improving cure rates at 21 days in people with diffuse acute otitis externa ( high-quality evidence ). Topical corticosteroid–acetic acid compared with topical acetic acid: Topical corticosteroid–acetic acid is more effective at improving cure rates at 21 days in people with diffuse acute otitis externa (high-quality evidence). Topical corticosteroid–antibacterial–glacial acetic acid compared with topical glacial acetic acid: Topical corticosteroid–antibacterial–glacial acetic acid is more effective at increasing the proportion of people with inactive disease at 4 weeks after treatment (moderate-quality evidence). RECURRENCE Topical corticosteroid–antibacterial compared with topical acetic acid: Topical corticosteroid–antibacterial is more effective at reducing the risk of recurrence at 21–48 days in people with diffuse acute otitis externa (high-quality evidence). Topical corticosteroid–acetic acid compared with topical acetic acid: Topical corticosteroid–acetic acid is more effective at reducing the risk of recurrence in people with diffuse acute otitis externa (high-quality evidence). NOTE We found no direct information about whether topical corticosteroids alone are better than placebo in the treatment of people with otitis externa. However, there is consensus that they are effective. We found no clinically important results about topical corticosteroids compared with oral antibiotics, topical antifungals, topical aluminium acetate drops, topical acetic acid, or other topical anti-infective agents in people with otitis externa.

Benefits

We found no systematic review.

Topical corticosteroids alone versus placebo:

We found no RCTs with sufficient follow up. One double-blind RCT with a short follow-up period compared budesonide drops versus placebo drops in a secondary-care setting for 7 days. It found that budesonide drops significantly improved symptoms and signs compared with placebo after 10 days (change from baseline in a global clinical score ranging from 0 [no symptoms/signs] to 3 [severe symptoms/signs]: –2.29 with budesonide v +0.23 with placebo; P = 0.001).

Topical corticosteroids alone versus topical aluminium acetate, topical antibacterials, topical antifungals, topical corticosteroids, topical acetic acid, or oral antibiotics:

We found no RCTs.

Low- versus high-potency corticosteroids:

We found no RCTs.

Topical corticosteroid–antibacterial compared with placebo:

See benefits of topical antibacterial agents (with or without corticosteroids).

Topical corticosteroid–acetic acid versus topical acetic acid:

See benefits of topical acetic acid.

Topical corticosteroid–antibacterial versus topical acetic acid alone:

See benefits of topical acetic acid.

Topical corticosteroid–antibacterial–acetic acid versus topical corticosteroid–antibacterial:

See benefits of topical antibacterial agents (with or without corticosteroids).

Harms

Topical corticosteroids versus placebo:

We found no RCTs with sufficient follow up. The RCT with short-term follow up found that a similar proportion of people using budesonide and placebo had adverse effects, including external ear canal disorders (sticky ear canal, ear wax), headache, and dizziness (10/30 [33%] with budesonide v 9/30 [30%] with placebo; significance not reported).

Topical corticosteroids alone versus topical aluminium acetate, topical antibacterials, topical antifungals, topical corticosteroids, topical acetic acid, or oral antibiotics:

We found no RCTs.

Low- versus high-potency corticosteroids:

We found no RCTs.

Topical corticosteroid–antibacterial compared with placebo:

See harms of topical antibacterial agents (with or without corticosteroids).

Topical corticosteroid–acetic acid versus topical acetic acid alone:

See harms of topical acetic acid.

Topical corticosteroid–antibacterial versus topical acetic acid:

See harms of topical acetic acid.

Topical corticosteroid–antibacterial–acetic acid versus topical corticosteroid–antibacterial:

See harms of topical antibacterial agents (with or without corticosteroids).

Comment

Clinical guide:

In current UK practice, most clinicians would use a combination of topical corticosteroid plus antibiotic agent as first-line treatment of acute otitis externa. Some argue that microbial swabs should be taken at first attendance to tailor antimicrobial treatment in persisting cases, but this is supported by only anecdotal evidence. If there are concerns of a possible underlying tympanic membrane perforation, then a topical quinolone may be used in preference to other potentially ototoxic antibiotic preparations. However, in an acute ear infection with discharge, it may be difficult to differentiate between an external- and middle-ear infection. We do not know if quinolones are as effective as aminoglycosides in treating middle-ear infections. In the UK, the consensus opinion is that aminoglycoside/corticosteroid combination therapy can be used if limited to a course of under two weeks. It may be that the lack of a corticosteroid/quinolone combined agent in the UK has discouraged the use of quinolones. Clinicians giving corticosteroids in combination with quinolones are required to write two separate prescriptions, which may also affect patient compliance.

Substantive changes

Topical corticosteroids Re-evaluation of the evidence led to a change in categorisation to Likely to be beneficial by consensus as in all RCTs reported in this option corticosteroids have been given in combination with another agent.

2008; 2008: 0510.
Published online 2008 June 26.

Acetic acid (topical) for treating otitis externa

Summary

SYMPTOM IMPROVEMENT Topical acetic acid–antibacterial–corticosteroid compared with topical antibacterial–corticosteroid: Neomycin–dexamethasone–acetic acid spray is more effective than framycetin–gramicidin–dexamethasone drops at improving signs and symptoms of severe acute or chronic diffuse otitis externa at 1 month ( moderate-quality evidence ). CURE RATES Topical acetic acid compared with topical antibacterial–corticosteroid: Topical acetic acid is less effective at increasing cure rates at 21 days in people with diffuse acute otitis externa ( high-quality evidence ). Topical acetic acid alone compared with topical acetic acid–corticosteroid: Topical acetic acid is less effective at increasing cure rates at 21 days in people with diffuse acute otitis externa (high-quality evidence). Topical acetic acid alone compared with topical antibacterial–corticosteroid–acetic acid: Topical glacial acetic acid spray is less effective at increasing the proportion of people with inactive disease at 4 weeks after treatment (moderate-quality evidence). RECURRENCE Topical acetic acid compared with topical antibacterial–corticosteroid: Topical acetic acid is less effective at reducing the risk of recurrence at 21–48 days in people with diffuse acute otitis externa (high-quality evidence). Topical acetic acid compared with topical acetic acid–corticosteroid: Topical acetic acid is less effective at reducing the risk of recurrence in people with diffuse acute otitis externa (high-quality evidence). NOTE We found no direct information about whether topical acetic acid is better than no active treatment.

Benefits

We found no systematic review .

Topical acetic acid versus placebo:

We found no RCTs.

Topical acetic acid versus topical aluminium acetate:

We found no RCTs.

Topical acetic acid versus topical antibacterial alone:

We found no RCTs.

Topical acetic acid versus topical antifungals:

We found no RCTs.

Topical acetic acid versus topical corticosteroids:

We found no RCTs.

Topical acetic acid versus oral antibiotics:

We found no RCTs.

Topical acetic acid versus topical antibacterial–corticosteroid:

We found one RCT (213 adults in primary care with any severity of diffuse acute otitis externa on otoscopy), which compared three treatments: acetic acid drops, triamcinolone–acetic acid drops, and dexamethasone–neomycin–polymyxin drops. All groups received aural toilet (suction or expandable sponge wick) as required. It found that topical acetic acid was significantly less effective than topical antibiotic–corticosteroid in reducing time to recovery, increasing cure rate at 21 days, and in reducing recurrence between 21 and 48 days (median time to recovery: 8.0 days with acetic acid v 6.0 days with antibiotic–corticosteroid drops, P value not reported; cure: 40/65 [62%] with acetic acid v 63/73 [86%] with antibiotic–corticosteroid drops; OR [antibiotic–corticosteroid v acetic acid] 3.9, 95% CI 1.7 to 9.1; recurrence: 21/47 [45%] with acetic acid v 14/68 [21%] with antibiotic–corticosteroid drops; OR [antibiotic–corticosteroid v acetic acid] 0.4, 95% CI 0.2 to 1.0).

Topical acetic acid versus topical acetic acid–corticosteroid:

We found one RCT (213 adults in primary care with any severity of diffuse acute otitis externa on otoscopy), which compared three treatments: acetic acid drops, triamcinolone–acetic acid drops, and dexamethasone–neomycin–polymyxin drops. All groups received aural toilet (suction or expandable sponge wick) as required. It found that topical acetic acid alone significantly increased time to recovery, reduced cure rate at 21 days, and significantly increased the risk of recurrence between 21 and 48 days compared with topical corticosteroid–acetic acid (median time to recovery: 8.0 days with acetic acid v 7.0 days with corticosteroid–acetic acid, P value not reported; cure: 40/65 [62%] with acetic acid v 54/61 [89%] with corticosteroid–acetic acid, OR [corticosteroid–acetic acid v acetic acid alone] 4.8, 95% CI 1.9 to 12.3; recurrence: 21/47 [45%] with acetic acid v 15/57 [26%] with corticosteroid–acetic acid; OR [corticosteroid–acetic acid v acetic acid alone] 0.3, 95% CI 0.1 to 0.7).

Topical acetic acid versus topical antibacterial–corticosteroid–acetic acid:

See benefits of topical antibacterial agents (with or without corticosteroids).

Topical acetic acid–antibacterial–corticosteroid versus topical antibacterial–corticosteroid:

See benefits of topical antibacterial agents (with or without corticosteroids).

Harms

Topical acetic acid versus placebo:

We found no RCTs.

Topical acetic acid versus topical aluminium acetate:

We found no RCTs.

Topical acetic acid versus topical antibacterial alone:

We found no RCTs.

Topical acetic acid versus topical antifungals:

We found no RCTs.

Topical acetic acid versus topical corticosteroids:

We found no RCTs.

Topical acetic acid versus oral antibiotics:

We found no RCTs.

T

opical acetic acid alone versus topical acetic acid–corticosteroid:

In the RCT, 74% of participants reported at least one adverse effect. Adverse effects included local burning, pain, and irritation, although the study reported no significant difference among the treatment groups (no data reported).

Topical acetic acid alone versus topical antibacterial–corticosteroid–acetic acid:

See harms of topical antibacterial agents (with or without corticosteroids).

Topical acetic acid–antibacterial–corticosteroid versus topical antibacterial–corticosteroid:

See harms of topical antibacterial agents (with or without corticosteroids).

Comment

None.

Substantive changes

Topical acetic acid One RCT comparing neomycin–dexamethasone–glacial acetic acid versus glacial acetic acid alone added; benefits data enhanced; categorisation unchanged (Unknown effectiveness). The RCT found that a larger proportion of people had inactive disease after treatment with neomycin–dexamethasone–glacial acetic acid compared with glacial acetic acid alone at 4 weeks.

2008; 2008: 0510.
Published online 2008 June 26.

Antibiotics (oral)

Summary

We found no clinically important results about whether oral antibiotics are better than no active treatment or topical anti-infective agents in people with otitis externa.

Benefits

We found no systematic review.

Oral antibiotics versus placebo:

We found no RCTs.

Oral antibiotics versus topical alumium acetata, topical antibacterials, topical antifungals, topical corticosteroids, or topical acetic acid:

We found no RCTs.

Harms

We found no RCTs.

Comment

None.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Antibiotics (oral) plus anti-infective agents (topical)

Summary

We found no clinically important results about whether oral antibiotics in combination with a topical anti-infective agent are better than a topical anti-infective agent alone in people with otitis externa. There is consensus that adding oral antibiotics to topical anti-infective agents will not confer additional benefit.

Benefits

We found no systematic review.

Oral antibiotics plus topical antibacterial versus topical antibacterial alone:

We found no RCTs.

Oral antibiotics plus topical antifungal versus topical antifungal alone:

We found no RCTs.

Harms

Oral antibiotics plus topical antibacterial versus topical antibacterial alone:

We found no RCTs.

Oral antibiotics plus topical antifungal versus topical antifungal alone:

We found no RCTs.

Comment

Oral antibiotics plus topical antifungal versus placebo:

One double-blind RCT with a short follow-up period compared 5 days of oral trimethoprim–sulfamethoxazole (co-trimoxazole) versus placebo in a primary-care setting. Both groups also received repeated applications of ointment containing triamcinolone, neomycin, and gramicidin, and had suction of the external canal if discharge was present. The RCT found no significant difference between groups in symptom severity scores, duration of symptoms, or cure rate (improvement in mean symptom severity score on scale ranging from 1 [no symptoms] to 5 [severe symptoms]: 0.72 with added oral co-trimoxazole v 0.69 with added placebo, P greater than 0.4; mean duration of symptoms: 3.1 days with added oral co-trimoxazole v 3.1 days with placebo, P greater than 0.5; cure rates: 18/47 [38%] with added oral co-trimoxazole v 21/53 [40%] with placebo, P greater than 0.8). The RCT gave no information on adverse effects.

Clinical guide:

There is consensus that adding oral antibiotics to topical anti-infective agents will not confer additional benefit in people with otitis externa.

Substantive changes

Oral antibiotics plus topical anti-infective agents Reevaluation of the evidence led to a change in categorisation to Unlikely to be beneficial by consensus.

2008; 2008: 0510.
Published online 2008 June 26.

Specialist aural toilet

Summary

CURE RATES Different types of specialist aural toilet compared with each other: We don't know whether ear wicks plus anti-infective drops are more effective than gauze impregnated with an anti-infective agent at increasing cure rates at 4 weeks in people with moderate to severe acute diffuse otitis externa ( low-quality evidence ). NOTE We found no direct information about whether specialist aural toilet is better than no active treatment.

Benefits

We found no systematic review.

Specialist aural toilet versus no aural toilet:

We found no RCTs.

Different types of specialist aural toilet versus each other:

One RCT in a secondary-care setting (94 people with moderate to severe acute diffuse otitis externa on otoscopy) compared an ear wick plus anti-infective drops (framycetin–gramicidin–dexamethasone or flumetasone) removed after 3 days versus ribbon gauze impregnated with anti-infective ointment (framycetin–gramicidin or triamcinolone–gramicidin–neomycin–nystatin) removed after 3 days. It found no significant difference between groups in resolution rates at 4 weeks (resolution defined as absence of symptoms and signs: 30/47 [64%] with ear wick v 33/47 [70%] with ribbon gauze; P = 0.58).

Harms

Different types of specialist aural toilet versus each other:

The RCT gave no information on adverse effects.

Comment

None.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Acetic acid (topical) for preventing otitis externa

Summary

We found no direct information on the effects of prophylaxis with topical acetic acid for people with otitis externa.

Benefits

We found no systematic review or RCTs of acetic acid drops or spray.

Harms

We found no RCTs.

Comment

None.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Corticosteroids (topical) for preventing otitis externa

Summary

We found no direct information on the effects of prophylaxis with topical corticosteroids for people with otitis externa.

Benefits

We found no systematic review or RCTs of corticosteroid drops or spray.

Harms

We found no RCTs.

Comment

None.

Substantive changes

No new evidence

2008; 2008: 0510.
Published online 2008 June 26.

Water exclusion

Summary

We found no direct information about water exclusion for prevention of otitis externa.

Benefits

We found no systematic review or RCTs.

Harms

We found no RCTs.

Comment

Clinical guide:

Most clinicians recommend water exclusion precautions for prevention, as well as treatment, of otitis externa. There is currently only anecdotal evidence to support this as an intervention, and RCTs to assess the effectiveness of this intervention are warranted.

Substantive changes

No new evidence


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