Topical antibiotics with steroids for chronic suppurative otitis media

Chronic suppurative otitis media (CSOM), sometimes referred to as chronic otitis media (COM), is a chronic inflammation and often polymicrobial infection of the middle ear and mastoid cavity that is characterised by ear discharge (otorrhoea) through a perforated tympanic membrane. The predominant symptoms of CSOM are ear discharge and hearing loss. Topical antibiotics aim 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 CSOM treatments, such as steroids, antiseptics or ear cleaning ('aural toileting'). Antibiotics are commonly prescribed in combined preparations with steroids. This is one of a suite of seven Cochrane reviews evaluating the effects of non-surgical interventions for CSOM. It is the first update of the original review published in 2020.

This review aims to assess the effects of adding a topical steroid to topical antibiotics in the treatment of people with chronic suppurative otitis media.

We searched the Cochrane ENT Specialised Register, CENTRAL, Ovid MEDLINE, Ovid EMBASE and five other databases on 15 June 2022. We also searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP).

We included randomised controlled trials (RCTs) that involved participants (adults and children) with chronic ear discharge of unknown cause or CSOM, where the ear discharge had continued for more than two weeks, and participants had been followed up for at least one week. The intervention of interest was any combination of a topical antibiotic agent(s) and a topical corticosteroid (steroid) applied directly into the ear canal.

We used standard Cochrane methods. Primary outcomes were: resolution of ear discharge or 'dry ear' (whether otoscopically confirmed or not), measured at three time points (between one and two weeks, two weeks to four weeks and after four weeks); health-related quality of life; 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 comparison and outcome.

This update found two new studies, bringing the total number of included studies to 19. The 19 studies addressed 13 treatment comparisons. The studies included a total of at least 2044 participants (one study of 40 ears did not report the number of participants). No studies reported health-related quality of life. 1. Topical antibiotics with steroids versus placebo or no treatment Three studies (210 participants) compared a topical antibiotic-steroid to saline or no treatment. Results for resolution of discharge were not reported at one to two weeks. One study (50 participants) reported results at more than four weeks, but they reported results by ear rather than by person, and it was not possible to adjust them. One study (123 participants) noted minor side effects in 16% of participants in both groups. One study (123 participants) reported no change in bone-conduction hearing thresholds and reported no difference in tinnitus or balance problems between groups. One study (50 participants) reported serious complications, but it was not clear which group these participants were from. However, we had only very low certainty about all these findings. 2. Topical antibiotics with steroids versus topical antibiotics alone (same antibiotics) Four studies (475 participants) evaluated this comparison. There may be little to no difference in resolution of discharge between topical antibiotic-steroid combinations compared to topical antibiotics alone at one to two weeks, but the evidence is very uncertain (risk ratio (RR) 1.08, 95% confidence interval (CI) 0.96 to 1.21; 3 studies, 335 participants; very low certainty evidence). No results for resolution of discharge after four weeks were reported. One study reported one case of local itchiness in each group (very low certainty evidence). One study (135 participants) investigated hearing, and three studies (395 participants) investigated suspected ototoxicity (very low certainty evidence). One study reported that no serious complications occurred during the study (110 participants; very low certainty evidence). 3. Topical antibiotics with steroids versus topical antibiotics alone (different antibiotics) Ten studies (1056 participants plus 40 ears) evaluated this comparison. Resolution of discharge may be more likely with quinolone topical antibiotics alone at one to two weeks compared with non-quinolone topical antibiotics (aminoglycosides) with steroids (RR 0.77, 95% CI 0.71 to 0.83; I² = 44%; 6 studies, 814 participants; low-certainty evidence), but results after four weeks are uncertain (RR 0.82, 95% CI 0.49 to 1.36; 1 study, 89 participants; very low certainty evidence). Two studies reported no serious complications (very low certainty evidence). One study reported results for ear pain or local irritation, bone-conduction hearing thresholds and suspected ototoxicity (very low certainty evidence). 4. Other comparisons Results from 10 other head-to-head comparisons are presented in the full review.

We are uncertain about the effectiveness of topical antibiotics with steroids for improving the resolution of ear discharge in participants with CSOM because we have low to very low certainty about the evidence available. The lack of certainty about the evidence is mainly due to the high risk of bias in the studies, imprecision in the effect estimates and publication bias. We found no evidence that the addition of steroids to topical antibiotics affects the resolution of ear discharge at one to two weeks, and no data were available for longer-term outcomes. There is low-certainty evidence that some types of topical antibiotics (without steroids) may be better than topical antibiotic-steroid combinations for improving resolution of discharge. There is uncertainty about the relative effectiveness of different types of antibiotics; it is not possible to determine whether quinolones are better, worse or the same as aminoglycosides. These two groups of compounds are believed to have different harmful effect profiles, but there is insufficient evidence from the included studies to make any comment about possible harms. In general, harmful effects were poorly reported. The evidence base is limited by the age of the studies, and lack of information relating to particular population groups or interventions.