The comparative in vitro killing activity of tea tree oil versus permethrin on Demodex folliculorum of rosacea patients

Abstract Background Demodex mites have been implicated in several cutaneous disorders compelling the research efforts for effective anti‐Demodex therapy. Objective Compare the survival time (ST) of Demodex folliculorum exposed to six different concentrations of tea tree oil (TTO) versus a positive control (permethrin 5%) and a negative control (immersion oil) group. Materials and methods The wastes of rosacea patients’ standardized superficial skin biopsy samples were recruited for the trial. The primary outcome measure of this study was the survival time, defined as the period between the exposure of study agents to the complete cessation of Demodex movements. Results All differences between the mean survival times of 2.5% (54.0 ± 6.1), 5% (39.0 ± 3.9), 10% (22.0 ± 2.5), 25% (13.0 ± 2.5), 50% (7.8 ± 0.6), and 100% TTO (3.3 ± 1.3) were significant ( p < 0.05). The ST of the negative control group was 196.0 ± 23.6 min. The ST of permethrin 5% was 12.5 ± 1.9 that did not show a statistically significant difference from the ST of TTO 25% ( p = 0.628). Conclusion The survival times of the six different TTO groups confirmed a dose‐related pattern, all of which had survival times shorter than the negative control (immersion oil). TTO 25% had comparable efficacy to the positive control agent (permethrin 5%).