Comparison of the in vitro Demodex folliculorum killing activity of azelaic acid and permethrin

Abstract

Aim: Demodex parasites have been linked to dermatological disorders, especially rosacea, without a proven mechanism. Moreover, some anti-Demodex agents demonstrate a dual therapeutic effect related to a direct effect on the skin disorder along with a decreased number of Demodex mites. Despite being considered a first-line treatment approach for rosacea, azelaic acid's efficacy against Demodex mites has not been investigated. In the current study, mites were continuously observed after exposure to the test agents to evaluate the potential anti-Demodex efficacy of azelaic acid. The efficacy of azelaic acid was compared to that of a positive control agent (permethrin).
 Material and Method: The wastes of diagnostic standardized skin surface biopsy samples of rosacea patients were collected for the trial. To four active treatment groups were administered 10% azelaic acid, 20% azelaic acid, 30% azelaic acid, and 5% permethrin. In addition, there was a control group, and 20 Demodex mites were included in each of the five groups. The authors conducted the real-time observation of the study groups through a digital microscope. The survival times of the mites were recorded and compared between the groups.
 Results: The mean survival time was 12.2±1.5 minutes in the 5% permethrin group. The mean survival times in the 10%, 20%, and 30% azelaic acid groups were 15.8±1.6, 14±1.5, and 12±1.2 minutes, respectively. The differences between the four active treatment groups did not reach statistical significance (p>0.05).
 Discussion: The present study’s results revealed that all three concentrations of azelaic acid had anti-Demodex efficacy comparable to that of 5% permethrin.