Title: Clinical Evidence of Lice Resistance to Over-the-Counter Products.
Author(s): Burkhart CG; Burkhart CN*
Author’s Address: Department of Medicine, Medical College of Ohio, Toledo, Ohio, USA.
Source: Journal of Cutaneous Medicine and Surgery. [J Cutan Med Surg] 2000 Oct; Vol. 4 (4), pp. 199-201.
Journal Information: Country of Publication: Canada NLM ID: 9614685 ISSN: 1203-4754 Subsets: MEDLINE
Abstract: BACKGROUND: Over-the-counter insecticidal solutions continue to be the mainstream treatment for most cases of head lice. Recorded insecticidal activity 15 years ago was at 100%, with ovicidal kill at 80%. Recently scattered accounts of possible resistance have surfaced.

OBJECTIVE: This article is to document the general consensus that head lice are becoming resistant to standard over-the-counter therapies.

METHODS: Direct testing of lethality of adult lice with permethrin and pyrethroid was assessed.

RESULTS: Present over-the-counter products proved to be successful in only 9 of 32 head lice tested (28% insecticidal activity).

CONCLUSIONS: Our series of cases further documents that over-the-counter head lice preparations no longer achieve high levels of insecticidal activity, suggesting increased resistance to these insecticides.

Database: MEDLINE

*The authors cited above are not in any way affiliated with Rainforest Essentials. Their citation is offered solely for informational purposes and not to be construed as an endorsement of Lice Off!™ in particular or any of our products in general.