Neem-silicone lotion and ultrasound nit comb: a randomised, controlled clinical trial treating head louse infestation

Ian F Burgess,Elizabeth R Brunton,Nazma A Burgess,Mark N Burgess

doi:10.1186/s41702-017-0009-0

Abstract

BackgroundA neem-based conditioner lotion (ONC) used against head lice was previously tested clinically and shown to be relatively ineffective. To improve the activity against lice and their eggs, it was reformulated into a silicone vehicle (NNC) as part of a project to improve pediculicidal medical devices. An ultrasound nit comb was also developed to be used in conjunction with the neem lotion to remove louse eggs from the hair.MethodsA single-centre, parallel group, randomised, controlled, open-label community-based clinical study was set up to test the NNC lotion in comparison with a marketed product based on isopropyl myristate and cyclomethicone (IPM/C) with two treatments 7 days apart. In parallel, the lubrication effects of the NNC and ONC lotions were compared in use with the ultrasound comb.ResultsFor 134 randomised participants (50 NNC, 53 IPM/C, 17 NNC plus comb, and 14 ONC plus comb), the cure rate was 72.0% for NNC and 69.8% for IPM/C (OR 1.112, 95% CI, 0.47 to 2.61). Additional combing gave 82.4% cure using NNC and 28.6% using ONC (OR 11.67; 95% CI 2.13 to 64.04). No difference in efficacy of nit removal was detected although combing with conditioner was physically easier.ConclusionsOne percent neem oil in silicone (NNC) is as effective to eliminate head lice as other silicone products. Nit combing is easier using a conditioner lubricant to facilitate sliding of the eggshells along hairs.Trial registrationCurrent Controlled Trials Registry ISRCTN77673809

Highlights

A neem-based conditioner lotion (ONC) used against head lice was previously tested clinically and shown to be relatively ineffective
Laboratory combing comparison The laboratory comparison of the two neem-based lubricants plus the ClearBrush® ultrasound comb found the silicone-based Reformulated Nice ‘n Clear head louse lotion (NNC) was a less-effective lubricant than the conditioner-based ONC, irrespective of the use of ultrasound
Ultrasound reduced both peak force and average force for all evaluations, but removing eggs treated with NNC was more difficult than removing eggs from dry, untreated hair (Fig. 3)

Summary

Introduction

A neem-based conditioner lotion (ONC) used against head lice was previously tested clinically and shown to be relatively ineffective. Apart from essential oils (Grieve et al 2007; Burgess et al 2010; Barker and Altman 2010), few plant products have undergone clinical trials. An alcohol-based Australian product, containing 6% neem oil and 16% eucalyptus, required two applications plus combing in a Thai study (Thawornchaisit et al 2012). Both results contrast strongly with our earlier low success using a neem oil-based conditioner plus combing (Brown and Burgess 2017)

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Discussion

Conclusion