Key message
– There is limited evidence comparing topical antibiotics with topical antiseptics in people with swelling and infection of the middle ear (called chronic suppurative otitis media). The evidence is very uncertain whether antibiotics or topical antiseptics are more effective for reducing ear discharge, except that topical antibiotics are likely to be more effective than boric acid (an antiseptic).
What is chronic suppurative otitis media?
Chronic suppurative otitis media is a long-term (chronic) swelling and infection of the middle ear, with ear discharge (otorrhoea) through a perforated tympanic membrane (where the eardrum has a hole or tear in it). The main symptoms of chronic suppurative otitis media are ear discharge (pus that leaks out from a hole in the eardrum) and hearing loss.
How can chronic suppurative otitis media be treated?
Antibiotics (which kill bacteria) are the most commonly used treatment for chronic suppurative otitis media. Antibiotics can either be 'topical' (put into the ear canal as ear drops, ointments, sprays, or creams) or 'systemic' (taken either by mouth or by an injection into a muscle or vein). Topical antiseptics (antiseptics put directly into the ear as ear drops or powders) are a possible treatment for chronic suppurative otitis media. Both antibiotics and topical antiseptics kill or stop the growth of the germs that may be responsible for the infection.
Antibiotics and topical antiseptics can be used on their own or added to other treatments for chronic suppurative otitis media, such as other antibiotics or ear cleaning (called aural toileting). It was important in this review to examine whether there were any unwanted effects from using antibiotics and antiseptics, such as irritation of the skin within the outer ear, which may cause discomfort, pain, or itching. Some antibiotics and antiseptics (such as alcohol) can also be toxic to the inner ear (called ototoxicity), which means that they may cause permanent hearing loss, dizziness, or ringing in the ear (called tinnitus).
What was the aim of this review?
We wanted to compare antibiotics and antiseptics for the treatment of chronic suppurative otitis media. In particular, we wanted to know whether they stopped ear discharge, and whether they affected people's quality of life or hearing. We also wanted to know if they caused pain, discomfort, or irritation in the ear; had unwanted effects such as dizziness or ear bleeding; or any serious complications. We compared and summarised the results of the studies and rated our confidence in the evidence, based on factors such as study methods and consistency of results.
What were the main results of the review?
We found 15 studies, which included 2371 people, that compared antibiotics to a variety of antiseptics (acetic acid, boric acid, povidone-iodine, and aluminium acetate). One study recruited only children, two studies recruited only adults, and 12 studies included both adults and children. About 40 in every 100 people were females. We presented the main comparisons below.
Comparison of antibiotics to acetic acid
We included seven studies (835 people). We have little to no confidence in the evidence of whether topical antibiotics or acetic acid improved ear discharge in people with chronic suppurative otitis media. It was not possible to know whether there was a difference between treatments for any other symptoms or effects that we were interested in.
Comparison of antibiotics to boric acid
We included two studies (532 people). Topical antibiotics (quinolones) are likely to be better than boric acid at reducing ear discharge after one to two weeks. There may also be less ear discomfort (pain, irritation, and bleeding). Topical quinolones may result in a greater improvement in hearing compared to topical boric acid, but this difference may be too small for the person to notice a difference.
Comparison of antibiotics to povidone-iodine
We included one study (40 people). We have little to no confidence in the evidence of whether topical or systemic antibiotics or povidone-iodine improve the resolution of ear discharge in people with chronic suppurative otitis media. It was not possible to know whether there was a difference between treatments for any other symptoms or effects that we were interested in.
Comparison of antibiotics to aluminium acetate
We included one study (51 people) that stated there was improvement in ear discharge at two to four weeks, but they did not present their results in a way that we could use. It was not possible to know whether there was a difference between treatments for any other symptoms or effects that we were interested in.
What are the limitations of the evidence?
The studies were small with many being poorly reported, and results varied widely between studies. We also need more information about harmful effects.
How up to date is this review?
This is the first update of a review published in 2020. The evidence is up to date to June 2022.
Read the full abstract
Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media, is a chronic inflammation and often polymicrobial infection of the middle ear and mastoid cavity. It is characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss.
Antibiotics and antiseptics kill or inhibit the micro-organisms that may be responsible for the infection. Antibiotics can be applied topically or administered systemically via the oral or injection route. Antiseptics are always directly applied to the ear (topically).
Objectives
To assess the benefits and harms of antibiotics versus antiseptics for people with chronic suppurative otitis media (CSOM).
Search strategy
We searched the Cochrane ENT Register, CENTRAL, Ovid MEDLINE, Ovid Embase, and five other databases. We also searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (ICTRP). The latest search date was 15 June 2022.
Selection criteria
We included randomised controlled trials (RCTs) with at least a one-week follow-up involving adults and children who had chronic ear discharge of unknown cause or CSOM, where ear discharge had continued for more than two weeks.
The intervention was any single, or combination of, antibiotic agent, whether applied topically (without steroids) or systemically. The comparison was any single, or combination of, topical antiseptic agent, applied as ear drops, powders, or irrigations, or as part of an aural toileting procedure.
The comparisons were 1. topical antiseptics compared to topical antibiotics, and 2. topical antiseptics compared to systemic antibiotics. We further separated these comparisons into those in which a. both groups of participants received aural toileting in addition to the intervention, or b. both groups received some other add-on therapy treatment (such as systemic antibiotics) to both arms.
Data collection and analysis
We used standard Cochrane methodology. Our primary outcomes were resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at between one week and up to two weeks, two weeks to up to four weeks, and after four weeks; health-related quality of life using a validated instrument; and ear pain (otalgia) or discomfort or local irritation. Secondary outcomes were hearing, serious complications, and ototoxicity. We used GRADE to assess the certainty of the evidence for each outcome.
Main results
This updated review included eight new studies. Overall, we identified 15 studies (2371 participants) across seven comparisons with antibiotics compared to acetic acid, aluminium acetate, boric acid, and povidone-iodine. None of the included studies reported health-related quality of life or serious complications.
1. Topical antibiotics (quinolones or aminoglycosides) versus topical antiseptic (acetic acid)
We included seven studies (835 participants).
Acetic acid may increase resolution of ear discharge when compared to aminoglycoside at one to two weeks (low-certainty evidence). It is very uncertain whether acetic acid may increase resolution of ear discharge at one to two weeks when compared to topical quinolone. Results after four weeks were only presented narratively. It is very uncertain whether acetic acid may cause more ear pain, discomfort, local irritation, or combinations of these compared to topical antibiotics (aminoglycosides and quinolones) (risk ratio (RR) 0.20, 95% confidence interval (CI) 0.03 to 1.12; I2 = 0%; 3 studies, 277 participants; very low-certainty evidence). An additional two studies (350 participants) provided narrative results. There may be little to no difference in hearing between groups reported narratively (quinolones; low-certainty evidence). The evidence is very uncertain for serious complications (aminoglycosides) or suspected ototoxicity (aminoglycosides) (very low-certainty evidence).
2. Topical antibiotics (quinolones) versus topical antiseptic (boric acid)
We included two studies (532 participants).
Topical quinolones are likely to increase resolution of ear discharge at one to two weeks compared with boric acid ear drops (RR 1.86, 95% CI 1.48 to 2.35; 1 study, 411 participants; moderate-certainty evidence). This means that one additional person will have resolution of ear discharge for every four people receiving topical antibiotics (compared with boric acid) at two weeks. No study reported results for ear discharge after four weeks. There may be less ear pain, discomfort, or irritation with quinolones compared with boric acid (RR 0.56, 95% CI 0.32 to 0.98; 2 studies, 510 participants; low-certainty evidence). Suspected ototoxicity and serious complications were not reported. Topical quinolones may result in a greater improvement in mean hearing from baseline compared to topical boric acid (mean difference (MD) 2.79 decibels, 95% CI 0.48 to 5.10; 1 study, 390 participants; low-certainty evidence), but this difference may not be clinically significant.
3. Topical antibiotics (quinolones) versus topical antiseptic (povidone-iodine)
We included one study (40 participants).
It is very uncertain if there is a difference between quinolones and povidone-iodine with respect to resolution of ear discharge at one to two weeks (RR 1.02, 95% CI 0.82 to 1.26; 1 RCT, 39 participants; very low-certainty evidence). The study reported qualitatively that there were no differences between the groups for hearing and no participants developed ototoxic effects (very low-certainty evidence). There were no results reported for resolution of ear discharge beyond four weeks; ear pain, discomfort, or irritation; or serious complications.
4. Topical antibiotics versus topical antiseptic (aluminium acetate)
We included one study (51 participants; 60 ears) that presented results for resolution of ear discharge at two to four weeks results narratively. No other results were reported.
5. Other comparisons
Five studies (966 participants) were assessed over an additional three comparisons; however, these results have not been included in the abstract.
Authors' conclusions
Treatment of CSOM with topical antibiotics (quinolones) likely results in an increase in resolution of ear discharge compared with boric acid at up to two weeks. There was limited evidence for the efficacy of other topical antibiotics or topical antiseptics and so we are unable to draw conclusions. Harmful effects were not well reported. Limitations of the review include lack of recent data, limitations in the quality of included studies, and limited information on certain population groups or interventions.
