Do Steroids Provide the Best Treatment for Otitis Externa?

Abstract & Commentary

Source: Van Balen FAM, et al. Clinical efficacy of 3 common treatments in acute otitis externa in primary care: Randomized controlled trial. BMJ 2003;327:1.

In this European study, researchers compared three different topical treatment regimens for patients with acute otitis externa: acetic acid alone, acetic acid with steroids (triamcinolone 0.1%), or antibiotic with steroids (neomycin/polymixin with dexamethasone). The investigators compared recovery days, cure, and recurrence rates during the 42 days following therapy.

Overall, 213 patients meeting explicit criteria (external auditory canal redness or swelling or debris associated with typical symptoms including pain, itch, otorrhea, hearing loss, or stuffy feeling fewer than three weeks in duration) were randomized to one of the three treatment regimens in a double-blind fashion. Patients were treated with each agent on a three-times-per-day basis from seven to 21 days based on physician evaluation for cure at seven, 14, and 21 days. Patients maintained daily logs of their symptoms and also were followed up at 42 days by telephone to assess for any recurrences.

Median duration of symptoms was shorter with steroids (7.0 days for acetic acid plus steroid and 6.0 days for antibiotic plus steroid) compared to acetic acid alone (8.0 days). More important, cure rates were markedly improved with the addition of steroids. Cure rates for acetic acid only, acetic acid plus steroid, and antibiotic plus steroid were 29.2%, 47.5%, and 42.5%, respectively, at seven days; 56.9%, 75.4%, and 82.2% at 14 days; and 61.5%, 88.5%, and 86.3% at 21 days. Recurrence rates at 42 days also were higher with acetic acid only (44.7%) compared to acetic acid plus steroid (26.3%) and antibiotic plus steroid (20.6%). In addition, there were no significant differences in adverse side effects between the three different regimens.

Based on their findings, the authors conclude that ear drops containing corticosteroids are more effective in the treatment of acute otitis externa, particularly when compared with acetic acid alone. In addition, the authors conclude that corticosteroids with either acetic acid or antibiotics are equally effective in terms of patient recovery, symptom resolution, cure rates, and recurrences.

Commentary by Theodore C. Chan, MD, FACEP

Patients with acute otitis externa commonly present to the emergency department. Standard treatment options have focused on rebuilding the natural acid-lipid layer protecting the external auditory canal, reducing soft tissue inflammation, and eradicating the infection, most commonly caused by pseudomonas species and staphylococcal bacteria. A myriad of treatments have included home remedies such as acetic acid (vinegar or commercially available VoSol) and isopropyl alcohol (rubbing alcohol), as well as more sophisticated antibiotic and steroid combinations similar to the antibiotic-steroid regimen arm in this study (such as Cortisporin Otic).

This study is a well-conducted, double-blind, randomized large clinical trial demonstrating that topical acetic acid with corticosteroids or antibiotics with steroids are superior to acetic acid alone in the treatment of acute otitis externa. However, while the investigators found the acetic acid plus steroid combination had similar efficacy to the antibiotic plus steroid combination, they did not compare these regimens against topical antibiotics alone.

Moreover, it is impressive to note that recurrence of symptoms within 42 days of therapy was common in all three treatment regimens. It is not clear what evaluation or treatment occurred for patients with recurrent symptoms.

Dr. Chan, Associate Clinical Professor of Medicine, Emergency Medicine, University of California, San Diego, is on the Editorial Board of Emergency Medicine Alert.