Systematic review of topical antimicrobial therapy for acute otitis externa

OBJECTIVE: To determine the efficacy of topical antimicrobials for acute otitis externa. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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. SIGNIFICANCE: Summary estimates from the 13 meta-analyses can be used to facilitate evidence-based management recommendations and clinical practice guideline development.