Objective: To compare the clinical efficacy of ear drops containing acetic acid, corticosteroid and acetic acid, and steroid and antibiotic in acute otitis externa in primary care.
Design: Randomised controlled trial.
Setting: 79 general practices, Netherlands.
Participants: 213 adults with acute otitis externa.
Primary outcome: duration of symptoms (days) according to patient diaries. Secondary outcome: cure rate according to general practitioner completed questionnaires and recurrence of symptoms between days 21 and 42.
Results: Symptoms lasted for a median of 8.0 days (95% confidence interval 7.0 to 9.0) in the acetic acid group, 7.0 days (5.8 to 8.3) in the steroid and acetic acid group, and 6.0 days (5.1 to 6.9) in the steroid and antibiotic group. The overall cure rates at seven, 14, and 21 days were 38%, 68%, and 75%, respectively. Compared with the acetic acid group, significantly more patients were cured in the steroid and acetic acid group and steroid and antibiotic group at day 14 (odds ratio 2.4, 1.1 to 5.3, and 3.5, 1.6 to 7.7, respectively) and day 21 (5.3, 2.0 to 13.7, and 3.9, 1.7 to 9.1, respectively). Recurrence of symptoms between days 21 and 42 occurred in 29% (50/172) of patients and was seen significantly less in the steroid and acetic acid group (0.3, 0.1 to 0.7) and steroid and antibiotic group (0.4, 0.2 to 1.0) than in the acetic acid group.
Conclusions: Ear drops containing corticosteroids are more effective than acetic acid ear drops in the treatment of acute otitis externa in primary care. Steroid and acetic acid or steroid and antibiotic ear drops are equally effective.