Topical antibiotics with steroids for chronic suppurative otitis media

Chronic suppurative otitis media (CSOM) is a chronic inflammation and often polymicrobial infection of the middle ear and mastoid cavity, characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Topical antibiotics act to kill or inhibit the growth of micro-organisms that may be responsible for the infection. Antibiotics can be used alone or in addition to other treatments for CSOM, such as steroids, antiseptics or ear cleaning (aural toileting). Antibiotics are commonly prescribed in combined preparations with steroids.

To assess the effects of adding a topical steroid to topical antibiotics in the treatment of people with chronic suppurative otitis media (CSOM).

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL via the Cochrane Register of Studies); Ovid MEDLINE; Ovid Embase; CINAHL; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 16 March 2020.

We included randomised controlled trials (RCTs) with at least a one-week follow-up involving participants (adults and children) who had chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks. The interventions were any combination of a topical antibiotic agent(s) of any class and a topical corticosteroid (steroid) of any class, applied directly into the ear canal as ear drops, powders or irrigations, or as part of an aural toileting procedure. The two main comparisons were topical antibiotic and steroid compared to a) placebo or no intervention and b) another topical antibiotic.

We used the standard Cochrane methodological procedures. We used GRADE to assess the certainty of the evidence for each outcome. 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; ear pain (otalgia) or discomfort or local irritation. Secondary outcomes included hearing, serious complications and ototoxicity.

We included 17 studies addressing 11 treatment comparisons. A total of 1901 participants were included, with one study (40 ears) not reporting the number of participants recruited, which we therefore could not account for. No studies reported health-related quality of life. The main comparisons were: 1. Topical antibiotics with steroids versus placebo or no treatment Three studies (210 participants) compared a topical antibiotic-steroid to saline or no treatment. Resolution of discharge was not reported at between one to two weeks. One study (50 'high-risk' children) reported results at more than four weeks by ear and we could not adjust the results to by person. The study reported that 58% (of 41 ears) resolved with topical antibiotics compared with 50% (of 26 ears) with no treatment, but the evidence is very uncertain. One study (123 participants) noted minor side effects in 16% of participants in both the intervention and placebo groups (very low-certainty evidence). One study (123 participants) reported no change in bone-conduction hearing thresholds and reported no difference in tinnitus or balance problems between groups (very low-certainty evidence). One study (50 participants) reported serious complications, but it was not clear which group these patients were from, or whether the complications occurred pre- or post-treatment. One study (123 participants) reported that no side effects occurred in any participants (very low-certainty evidence). 2. Topical antibiotics with steroids versus topical antibiotics (same antibiotics) only Four studies (475 participants) were included in this comparison. Three studies (340 participants) compared topical antibiotic-steroid combinations to topical antibiotics alone. The evidence suggests little or no difference in resolution of discharge at one to two weeks: 82.7% versus 76.6% (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.96 to 1.21; 335 participants; 3 studies (4 study arms); low-certainty evidence). No results for resolution of discharge after four weeks were reported. One study (110 participants) reported local itchiness but as there was only one episode in each group it is uncertain whether there is a difference (very low-certainty evidence). Three studies (395 participants) investigated suspected ototoxicity but it was not possible to determine whether there were differences between the groups for this outcome (very low-certainty evidence). No study reported serious complications. 3. Topical antibiotics with steroids compared to topical antibiotics alone (different antibiotics) Nine studies (981 participants plus 40 ears) evaluated a range of comparisons of topical non-quinolone antibiotic-steroid combinations versus topical quinolone antibiotics alone. Resolution of discharge may be greater with quinolone topical antibiotics alone at between one to two weeks compared with non-quinolone topical antibiotics with steroids: 82.1% versus 63.2% (RR 0.77, 95% CI 0.71 to 0.84; 7 studies; 903 participants, low-certainty evidence). Results for resolution of ear discharge after four weeks were not reported. One study (52 participants) reported usable data on ear pain, two studies (419 participants) reported hearing outcomes and one study (52 participants) reported balance problems. It was not possible to determine whether there were significant differences between the groups for these outcomes (very low-certainty evidence). Two studies (149 participants) reported no serious complications (very low-certainty evidence).

We are uncertain about the effectiveness of topical antibiotics with steroids in improving the resolution of ear discharge in patients with CSOM because of the limited amount of low-certainty evidence available. Amongst this uncertainty, we found no evidence that the addition of steroids to topical antibiotics affects the resolution of ear discharge. There is also low-certainty evidence that some types of topical antibiotics (without steroids) may be better than topical antibiotic/steroid combinations in improving resolution of discharge. There is also uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine with any certainty whether or not quinolones are better or worse than aminoglycosides. These two groups of compounds have different adverse effect profiles, but there is insufficient evidence from the included studies to make any comment about these. In general, adverse effects were poorly reported.