Treatment of Head Louse Infestation with a Novel Mixture Made of Semi-Crystalline Polymers and Plant Extracts: Blind, Randomized, Controlled, Superiority Trial

• Main Authors: José Henrique Leal Cardoso, Andrelina Noronha Coelho de Souza, Francisco Militão de Souza, Samia Sa Preire, Claire Pinçon
• Format: Article
• Language: English
• Published: MDPI AG 2020-04-01
• Series: Cosmetics
• Subjects: head lice; treatment; shampoo; <i>Pediculus humanus capitis</i>; clinical trial; clinical study
• Online Access: https://www.mdpi.com/2079-9284/7/2/25

The rate of head louse infestations is increasing. Most of the neurotoxic treatments are not reliably ovicidal and are faced with genetic resistance. The treatments based on a mechanical mode of action show no sufficient efficacy, transferring the chances of a cure on a tedious combing or leaving the hair fatty. This double-blinded, randomized, controlled, superiority trial evaluates the efficacy and safety of a novel mixture made of semi-crystalline polymers and plant extracts. Forty-five participants received a single application of either 1% Permethrin lotion or the novel lotion, applied for 15 minutes. Untreated and treated nits were collected and placed in an incubator during 10 days. The worst case intent-to-treat analysis found the novel lotion significantly more effective than 1% Permethrin, with 21/22 (95.5%) participants cured and 9/23 (39.1%), respectively (<i>p</i> < 0.0001). Rate of viable nymphs was 0.5 (2.1) for the new lotion and 40.8 (20.4) for the 1% Permethrin. The new lotion cures head louse infestations, offering an effective alternative treatment, with a high efficacy for inhibiting the hatching of eggs. Its physical actions on lice and their eggs should not be affected by resistance to neurotoxic insecticides.