Otitis externa: clinical comparison of local ciprofloxacin versus local oxytetracycline, polymyxin B, hydrocortisone combination treatment.

Thirty patients with otitis externa were included in a prospective, randomized, parallel group comparison study. Treatment regimens used were ciprofloxacin (2 mg/ml) as ear drops twice daily or drops containing oxytetracycline (5 mg/ml) polymyxin B (10,000 units/ml) and hydrocortisone (15 mg/ml) twice daily for 7 days. Evaluation was by clinical signs and symptoms and bacteriological findings from ear swabs prior to and 3 and 8 days after start of therapy, together with long-term follow-up if necessary. Sixteen patients were included in the ciprofloxacin and 14 in the combined antibiotic group. Six of 16 and 7 of 14 initial swabs, respectively, contained Pseudomonas aeruginosa. Mixed Gram-negative and Gram-positive pathogens were found in 3 patients in the ciprofloxacin group. All Gram-negative isolates were sensitive to ciprofloxacin. Microbiological evaluation showed rapid eradication of all bacterial pathogens in the ciprofloxacin group with 1 persistence of Candida albicans but eradication of Staphylococcus aureus in the same ear with marked clinical improvement. There was 1 case of supercolonization in the ciprofloxacin group with Candida parapsilosis. In the combined antibiotic group, there were 7 persistencies of which 5 were P. aeruginosa. No adverse effects were noted in either group. Treatment was assessed as a complete success in 14/16 and 5/14 cases, partial success in 2/16 and 4/14 cases and unsuccessful or indeterminate in 0/16 and 5/14 cases, respectively. Ciprofloxacin thus appears to be a useful and effective agent in the local therapy of otitis externa.