Adjunctive Agent for Treating Scabies: In vitro Killing Activity of Permethrin and Tea Tree Oil on Sarcoptes scabiei Collected from Patients

Objective: Recently, there has been a serious increase in cases of scabies. The number of patients who do not benefit from the current treatment agents is also quite high. There are publications showing that scabies mites are permethrin-resistant and ivermectin. The treatment with scabicides usually lasts for several hours and usually the treatment is repeated for at least another time, which reduces the patient's compliance with the treatment, especially in pediatric patients where the toxic effects of the products are more pronounced. Therefore there is a need for treatment modalities that are less toxic to humans. To observe the in vitro effect of tea tree oil (TTO) on S. scabiei and to compare it with those of permethrin.

Methods: Scabies specimens were removed from the patient and examined using a digital microscope. Parasites that were not damaged during sampling, and showed full motion were included in the study. No treatment was applied to the patients before removal of the mites. A total of 40 parasites were included in the study, with 10 parasites in each group. Immersion oil was applied to the control group, 5% permethrin to the first treatment group, while 5% and 25% TTO were used for the second and third study groups.

Results: The mean survival time (ST) of scabies mites in the 5% permethrin group was 350±31.3 min, while this for 5% TTO group 180±15.1 min and 120±13.3 min in the 25% TTO group. The mean ST of the sarcoptes in the control group was 2.820±90 min. The mean ST between the control, permethrin and TTO groups was statistically significant (p=0.03). ST between 5% and 25% TTO groups was also statistically significant (p=0.04). There were no statistical differences between permethrin and 5% or 25% TTO.

Conclusion: TTO has an acaricidal effect on S. scabiei. Although not used as the treatment of choise, it can be used as a supportive agent. Since it shows an acaricidal effect within a short time, it could be used as a shampoo or shower gel to enhance the acaricidal activity of another scabicide.