The effect of cold plasma on the treatment of external otitis: an experimental study in rats

In this paper we investigate the influence of cold plasma as novel method on the external otitis treatment which is a frequent cause of earache. 24 infected external auditory canals in 24 rats were categorized in four experimental groups including control, plasma exposed, ciprofloxacin drug and mixed of plasma-ciprofloxacin groups. In plasma group, dielectric barrier discharge was employed as the source of cold plasma in 5 days. All rats were observed with otoscope daily and a scoring system was used to evaluate swelling and effusion of the ear canal. Number of colonies in microbiological culture were counted in each group during the first 5 days after treatment. For the multiple group comparisons of swelling and effusion measured in the external auditory canal, Kruskal-Wallis analysis was applied and one-way anova and Kruskal-Wallis analysis was used for the statistical analysis of the results of the cultures in different days. Also, Tukey and Mann-Whitney tests was applied for multiple comparisons. Our findings show that swelling and effusion were obviously reduced in plasma group compared to control group (P < 0.01). Number of colonies in control group was statistically different from those in drug, plasma, and mixed group on the second to fifth day (p < 0.001). According to the results cold plasma can be introduced as an impressive method for external otitis treatment. Moreover, when cold plasma joined to antibiotic method, it leads to a superior performance respecting plasma or antibiotic method alone.