Efficacy and Safety of a Water-Based Head Lice Lotion: A Randomized, Controlled, Investigator-Blinded, Comparative, Bicentric Study

Abstract

Introduction Silicones (e.g., dimethicone) are effective and safe alternatives to insecticides for the treatment of head lice. However, silicones are lipophilic substances and do not only leave the hair greasy but they are also difficult to wash out. We have evaluated the efficacy and safety of a potential solution to this problem: an aqueous dispersion of a novel silylated polyol that has the same mode of action as dimethicone (suffocation) without its negative impact on hair characteristics. Methods This was a randomized, controlled, investigator-blinded, bicentric study that was conducted at two locations in the state of Florida (USA) to compare the test product (medical device) to a pyrethrum-based pediculicide that is a first-line, prescription-free treatment against head lice in the USA. The subjects ( n = 70) were randomly divided into two groups of 35 persons (test product group and reference product group), with each participant receiving two applications (day 0 and 7) of the product to be tested, according to the instructions for use. Efficacy and safety was evaluated at distinct time points. The primary objective was to establish a cure rate for the test product that was better than 70% at study end (day 10). Esthetic effects of the test product versus dimethicone were evaluated in a blinded, cross-over consumer study ( n = 100). Results At study end, the cure rate (corrected for re-infestation) of 88.2% with the test product significantly surpassed the pre-defined target of 70%, and thus the superiority of the test product versus the reference product was confirmed. The number of subjects cured (free of head lice) after the first treatment was remarkably higher with the test product than with the reference product (57.1 vs. 2.9%, respectively). Both products were safe and well tolerated and both showed beneficial esthetical effects. The consumer test demonstrated that the test product had better washing-out properties than dimethicone, as reflected by a significantly lower average rinsing time and number of washings required to restore the visual aspect of the hair, especially in terms of greasiness. Conclusion Aqueous dispersions of silylated polyols are a promising new class of pediculicides that combine high cure rates with optimal user convenience (short treatment period, easy wash-out with positive effect on hair quality). Trial Registration ClinicalTrials.gov identifier, NCT03617926. Funding Oystershell Laboratories.

Comparative efficacy of three pediculicides to treat head lice infestation in primary school girls: a randomised controlled assessor blind trial in rural Iran

“…Nowadays, resistance-prone insecticide-based products for the treatment of pediculosis are gradually going to be replaced by alternative new preparations with a physical mode of action. These silicone-based products are both safe and clinically effective [10, 20–22, 28, 29]. It is found in this study that dimeticone 4% is more efficacious in curing head lice infestations than either 1% permethrin or 0.2% d-phenothrin solutions using two interventions a week apart.…”

Pediculicide regulations and usage trends in Türkiye in 2015–2022

“…40 Many studies have reported the high efficacy and cure rates of DMT lotions applied twice, 7 days apart, for 8 hours or overnight. 30,41 In a randomized controlled trial, Burgess et al 42 reported that a single application of 4% dimethicone liquid gel for 15 minutes was more effective than two applications of 1% PER.…”

“…4,5 In the United Kingdom, the approximate equivalent cost per family member was €6.20-7.40 for DMT and €8.30-16.60 for treatment with PER. 41 In the United States, the cost of treating head lice was estimated at $365 million in 2004, with OTC products being less expensive than those available with a prescription. 50 However, this amount does not include the indirect costs of lice treatment, such as physician visits, purchase of lice combs, time spent removing nits/eggs from the scalps of infested individuals in institutions, and, most importantly, the cost of parental work absenteeism, especially where no-nit policies are implemented.…”

“…However, not all DMTs have been tested under clinical conditions, and it is possible that some products are less effective 40 . Many studies have reported the high efficacy and cure rates of DMT lotions applied twice, 7 days apart, for 8 hours or overnight 30,41 . In a randomized controlled trial, Burgess et al 42 .…”

Common pediatric infestations: update on diagnosis and treatment of scabies, head lice, and bed bugs

“…The efficacy of dimeticone has been shown in in vitro assays and randomized clinical trials, but it is not approved for use as a pediculicide by the FDA [44,45]. A class of water-based pediculicides that uses aqueous dispersions of silylated polyols shows promise in treating head lice and reducing the 'greasy' feeling in the hair that may remain after dimeticone use [46].…”