Systematic review of topical antimicrobial therapy for acute otitis externa

To determine the efficacy of topical antimicrobials for acute otitis externa.

Systematic review and random effects meta-analysis of randomized, controlled trials with parallel groups permitting one or more of the following comparisons: antimicrobial vs placebo, antiseptic vs antimicrobial, quinolone antibiotic vs nonquinolone antibiotic, steroid-antimicrobial vs antimicrobial, or antimicrobial-steroid vs steroid.

Twenty trials met inclusion criteria and 18 had data suitable for pooling. Topical antimicrobials increased absolute clinical cure rates over placebo by 46% (95% confidence interval [CI], 29% to 63%) and bacteriologic cure rates by 61% (95% CI, 46% to 76%). No significant differences were noted in clinical cure rates for other comparisons, except that steroid alone increased cure rates by 20% compared with steroid plus antibiotic (95% CI, 3% to 38%). Quinolone drops increased bacteriologic cure rates by 8% compared with nonquinolone antibiotics (95% CI, 1% to 16%), but had statistically equivalent rates of clinical cure and adverse events.

Topical antimicrobial is highly effective for acute otitis externa with clinical cure rates of 65% to 80% within 10 days of therapy. Minor differences were noted in comparative efficacy, but broad confidence limits containing small effect sizes make these of questionable clinical significance.

Summary estimates from the 13 meta-analyses can be used to facilitate evidence-based management recommendations and clinical practice guideline development.