External otitis caused by infection with Pseudomonas aeruginosa or Candida albicans cured by use of a topical group III steroid, without any antibiotics.

CONCLUSIONS: Irrespective of the microbial agent, group III steroid solution cured external otitis efficiently in a rat model. The addition of antibiotic components to steroid solutions for the treatment of external otitis is of questionable validity.
OBJECTIVE: External otitis, caused by infection with either Pseudomonas aeruginosa or Candida albicans, was established in a rat model and the treatment efficacy of a group III steroid solution was studied.
MATERIAL AND METHODS: Three treatments were studied: (i) a group III steroid solution; (ii) a group I steroid combined with two antibiotic components; and (iii) a saline solution. A scoring scale was used to evaluate the characteristics of the ear canal skin. Bacteriological and fungal samples were collected for culturing and ear canal skin biopsies were taken for structural analyses.
RESULTS: It was possible to cause P. aeruginosa and C. albicans infections in an animal model. In the P. aeruginosa-infected animals, only the group III steroid treatment cured all the animals. In the C. albicans-infected animals, group III steroid treatment resolved external otitis faster than the other treatment modalities.