Comparing the efficacy of three methods of permethrin application in pediculosis capitis: A randomized clinical trial

BACKGROUND: Pediculosis capitis, also known as head lice, is a common problem that affects individuals of different socio-economic backgrounds. Permethrin is generally considered the first-line treatment option for head lice. AIMS: The objective of this study was to evaluate and compare the therapeutic effects of three different methods of permethrin treatment for head lice. METHOD: A parallel, randomized clinical trial was conducted on 157 patients with head lice. The participants underwent eye examination and dry combing by a trained professional. The subjects were randomly divided into three groups and treated with one of the three methods of permethrin application: permethrin shampoo for 10 min, permethrin shampoo for 1 h, or permethrin cream for 10 min on a weekly basis for 3 weeks. RESULTS: Of the 157 participants, 154 completed the study. The group treated with permethrin shampoo for 1 h had the shortest average time for eradication of lice at 1.226 ± 0.422 weeks, which was significantly lower than the other two groups. Additionally, the 1-h permethrin shampoo group had the lowest time for scalp itching of 2.15 ± 0.632 weeks, which was significantly lower than the other two groups. Moreover, the rate of lice eradication in the first week was significantly higher in the 1-h permethrin shampoo group. CONCLUSION: The results of this study suggest that the use of 1% permethrin shampoo for 1 h is more effective in eradicating head lice within the first week of treatment and in relieving scalp itching during the second week.