Assessment of the efficacy and safety of a new treatment for head lice

Pediculosis and Factors Affecting Its Prevalence among Schoolchildren in Amol City, Northern Iran

Background

Head louse infestation, pediculosis, is a serious health problem worldwide. Infected children usually suffer from itching, allergies, and secondary infections besides psychological disorders such as depression and lack of self-confidence leading to school failure. This study aimed to investigate the status of pediculosis and its determinant factors among schoolchildren in Amol City, Northern Iran.

Methods

This study included 228 schools frequented by about 20017 students. Pediculosis was determined by careful examination of students' hair on the scalp, back of the neck, and around the ears. The diagnosis was based on observation of live adults, nymphs, and nits. A questionnaire was used to record the personal and demographic characteristics of participants.

Results

This study revealed that the prevalence of pediculosis among schoolchildren during all schooling seasons (autumn, winter, and spring) correlated with sex: the prevalence being higher among girls than boys (p= 0.00). In addition, the highest rates of pediculosis occurred during the autumn season (p= 0.00). The public schools accommodated higher numbers of louse-infected students than the private ones (p= 0.00). While head louse occurred at higher frequencies in long hair over the schooling year, dandruff had anti-louse effects (p= 0.00) during cold seasons, autumn, and winter. Socioeconomic status and educational level of parents played determinant roles in head louse prevalence (p= 0.00). Schoolchildren coming from socioeconomically well-situated families had lower rates of head louse infestation.

Conclusion

Our results showed that head pediculosis was a serious health problem among schoolchildren in Amol city and its prevalence and severity tended to be multifactorial.

Physically Acting Treatments for Head Lice—Can We Still Claim They Are ‘Resistance Proof’?

Head lice worldwide have developed resistance to insecticides, prompting the introduction of a range of alternative treatments including plant extracts and natural and synthetic oils. Clinical studies of physically acting treatments showed them to be highly effective when first introduced, and a widely held, but unsubstantiated, belief is that lice are unlikely to develop resistance to them. However, this ignores possibilities for natural selection of traits enabling lice to survive exposure. More recent investigations of some physically acting products have shown reduced efficacy, suggesting either changes of behavior, physical structure, or physiology of some louse populations. In addition, the activity of surfactants and similar compounds, acting as solubilizing agents of insect cuticular lipids, can be compromised by the widespread use of toiletry products containing similar substances. Hitherto, most clinical investigations have provided “best case” data resulting from investigator application of treatments. In the few studies involving participant application, the effectiveness was reduced, suggesting that consumer use allows some insects to survive, which could then be selected for tolerance. Unlike neurotoxic insecticides, there is no straightforward method to test for the activity of physically acting chemicals other than by clinical investigations, which need to be rigorous to eliminate poorly effective products as a way of ensuring the continued effectiveness of those treatments that are successful in eliminating infestation.

Head Lice

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among caregivers of school-aged children and adolescents. Since the 2015 clinical report on head lice was published by the American Academy of Pediatrics, new medications have been approved, and an algorithm for management of affected patients is included. This revised clinical report clarifies current diagnosis and treatment protocols.

Safety, Efficacy, and Physicochemical Characterization of Tinospora crispa Ointment: A Community-Based Formulation against Pediculus humanus capitis

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of 6.92±0.09. It has spreadability value of 15.04±0.98 g·cm/sec and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control Kwell^®, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.