Physically acting products for head lice – the end of the beginning
- Published
- Accepted
- Subject Areas
- Health Policy, Infectious Diseases, Pharmacology, Public Health, Ethical Issues
- Keywords
- pediculicide, physically acting, silicones, surfactants, treatment failure, treatment resistance
- Copyright
- © 2018 Burgess
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Physically acting products for head lice – the end of the beginning. PeerJ Preprints 6:e27412v1 https://doi.org/10.7287/peerj.preprints.27412v1
Abstract
Treatment of head louse infestation has evolved from widespread use of neurotoxic insecticides that have been extensively affected by resistance since the mid-1990s into the use of so-called physically acting treatments. It is widely believed that physically acting products are effectively “resistance proofed” because they do not act to inhibit any particular physiological mechanism and most have some kind of occlusive effect on the target organism. Over the past 20 years various new active materials have been utilized ranging from natural oils, synthetic oils, through to surfactants both as excipients and active substances. Relatively few of these products have been adequately tested clinically and, of those that have, there is now some indication that they are less effective than when first introduced. The question therefore arises whether lice can become resistant to these physically acting products. Only adequate testing both in the laboratory and in clinical trials can determine their real effectiveness and claiming efficacy based on the presence of a named chemical rather than demonstrated activity may result in acquired resistance to these types of product also.
Author Comment
This article was designed to question whether physically acting treatments for head louse infestation are as reliable and likely to remain as reliable as suggested and claimed by manufacturers. There is a widespread belief that products working by having physical effects cannot select for resistance but even the pivotal clinical evidence, where such evidence exists, does not support such a confident stance. Resistance to a physically acting treatment is unlikely to present itself in a clear and unambiguous manner, unlike resistance to conventional insecticides, but it is a potential problem that manufacturers, investigators, and even regulators should consider in order to avoid losing the products that consumers want.