In Vitro and In Vivo Evaluation of Infestation Deterrents Against Lice.

The human head louse is a cosmopolitan ectoparasite and frequently infests many people, particularly school-age children. Due to widespread pyrethroid resistance and the lack of efficient resistance management, there has been a considerable interest in the protection of uninfested people and prevention of reinfestation by disrupting lice transfer. In this study, two nonclinical model systems (in vitro and in vivo) were used to determine the efficacy of the infestation deterrents, Elimax lotion and Elimax shampoo, against human head lice or poultry chewing lice, respectively. With in vitro assessments, female head lice exhibited significantly higher avoidance responses to hair tufts treated with either of the test formulations, which led to significantly higher ovipositional avoidance when compared with female lice on control hair tufts. Additionally, both formulations were determined to be competent infestation deterrents in a competitive avoidance test in the presence of a known attractant (head louse feces extract). In in vivo assessments using a previously validated poultry model, Elimax shampoo was determined to be an efficacious deterrent against poultry chewing lice within Menopon spp. and Menacanthus spp.

Effect of Environmental Conditions and Toxic Compounds on the Locomotor Activity of Pediculus humanus capitis (Phthiraptera: Pediculidae).

In this work, we evaluated the effect of environmental variables such as temperature, humidity, and light on the locomotor activity of Pediculus humanus capitis. In addition, we used selected conditions of temperature, humidity, and light to study the effects of cypermethrin and N,N-diethyl-3-methylbenzamide (DEET) on the locomotor activity of head lice. Head lice increased their locomotor activity in an arena at 30°C compared with activity at 20°C. When we tested the influence of the humidity level, the locomotor activity of head lice showed no significant differences related to humidity level, both at 30°C and 20°C. Concerning light influence, we observed that the higher the intensity of light, the slower the movement of head lice. We also demonstrated that sublethal doses of toxics may alter locomotor activity in adults of head lice. Sublethal doses of cypermethrin induced hyperactivated responses in adult head lice. Sublethal doses of DEET evocated hypoactivated responses in head lice. The observation of stereotyped behavior in head lice elicited by toxic compounds proved that measuring locomotor activity in an experimental set-up where environmental conditions are controlled would be appropriate to evaluate compounds of biological importance, such as molecules involved in the host-parasite interaction and intraspecific relationships.

In the clinic. Common cutaneous parasites.

This issue provides a clinical overview of Common Cutaneous Parasites focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic.

Treatment of head lice (Pediculus humanus capitis) infestation: is regular combing alone with a special detection comb effective at all levels?

Head lice infestation (HLI) caused by Pediculus humanus capitis has been a public health problem worldwide. Specially designed combs are used to identify head lice, while anti-lice products are applied on the scalp for treatment. In the present study, we aimed to test whether combing only by precision detection comb (PDC) or metal pin comb (MPC) could be effective alternatives to the use of anti-lice products in children. A total of 560 children from two rural schools in Turkey were screened. In the PDC trial, children were combed every second day for 14 days, while in the MPC trial, combing was performed once in every four days for 15 days. Children were divided into two groups (dry combing and wet combing) for both trials and results were compared. The results showed no significant differences between dry and wet combing strategies for both combs for the removal of head lice (p > 0.05). The number of adult head lice declined significantly on each subsequent combing day in both approaches, except on day 15 in the MPC trial. In the end, no louse was found in 54.1 and 48.9% of children in the PDC and MPC trials, respectively. Since family members of infested children were not available, they were not checked for HLI. Four times combing within 2 weeks with MPC combs was found effective for both treatment of low HLI and prevention of heavy HLI. In conclusion, regular combing by special combs decreases HLI level in children and is safely applicable as long-term treatment.

A systematic literature review of pediculosis due to head lice in the Pacific Island Countries and Territories: what country specific research on head lice is needed?

BACKGROUND: Lack of guidelines on control of pediculosis in the Solomon Islands led to a search for relevant evidence on head lice in the Pacific Island Countries and Territories (PICTs). The aim of this search was to systematically evaluate evidence in the peer reviewed literature on pediculosis due to head lice (Pediculus humanus var capitis) in the 22 PICTs from the perspective of its value in informing national guidelines and control strategies. METHODS: PubMed, Web of Science, CINAHL and Scopus were searched using the terms (pediculosis OR head lice) AND each of the 22 PICTs individually. PRISMA methodology was used. Exclusion criteria were: i) not on topic; ii) publications on pediculosis not relevant to the country of the particular search; iii) in grey literature. RESULTS: Of 24 publications identified, only 5 were included. Four related to treatment and one to epidemiology. None contained information relevant to informing national guidelines. CONCLUSIONS: Current local evidence on head lice in the PICTs is minimal and totally inadequate to guide any recommendations for treatment or control. We recommend that local research is required to generate evidence on: i) epidemiology; ii) knowledge, attitudes and practices of health care providers and community members; iii) efficacy of local commercially available pharmaceutical treatments and local customary treatments; iv) acceptability, accessibility and affordability of available treatment strategies; and iv) appropriate control strategies for families, groups and institutions. We also recommend that operational research be done by local researchers based in the PICTs, supported by experienced head lice researchers, using a two way research capacity building model.

Demystifying pediculosis: school nurses taking the lead.

The treatment of Pediculosis capitis, or head lice, is fraught with misinformation, myths, and mismanagement. Common myths include the need to exclude children from school, the need to remove all visible nits ("no-nit" policies), the need for massive environmental cleaning, that head lice live for long periods of time, and that schools are a common location for lice transmission. Head lice are a common childhood nuisance, causing embarrassment and emotional trauma in both children and families. This article explores and challenges the commonly held beliefs about the identification, management, and treatment of Pediculosis by presenting current recommended evidence-based practice. It also challenges pediatric nurses, and school nurses in particular, in alignment with the National Association of School Nurses (NASN) Position Statement on Pediculosis Management in the School Setting, to act as change agents for reasonable and effective school policies and practices.

Wet combing for the eradication of head lice.

Manual removal (using conditioner and comb or a wet comb) can be used in the treatment of head lice. Head lice infestation (Pediculosis humanus capitis) is a common problem. It is diagnosed by visualising the lice. As half of people infested with head lice will not scratch, all people in contact with a person affected with head lice should be manually checked for infestations. Wet combing is easily and safely performed at home, but persistence is needed. This article describes the process of head lice removal using a wet comb. It has NHMRC Level 2 evidence of efficacy and no serious adverse effects have been reported.

Losing the louse: how to manage this common infestation in children.

This article aims to provide an overview of the symptoms, diagnosis, and treatment for lice infestations in children. Management of the condition by parents in the home is presented, as well as ways to prevent spread in the community. Nurses in acute care, outpatient, and school settings may use this information to teach families how to prevent a lice infestation and treat an infestation when it occurs.

Explaining the Determinants of Pediculosis Control and Prevention: A Qualitative Study in Southern Iran.

In many regions of the world, human head lice infestations caused by Pediculus capitis are a major health concern among school-aged children. This study was carried out to explain variables influencing pediculosis prevention and control from the perspective of parents and teachers of female elementary school pupils, as well as healthcare practitioners in Bandar Abbas, Iran. Participants in this qualitative study included 23 participants, including parents and teachers of primary school girls, as well as healthcare practitioners. Purposive sampling was employed and sustained until data saturation was reached. Data was acquired through in-depth interviews and evaluated using content analysis in the form of constant comparison. To assess the quality of the outcomes, Lincoln and Guba's criteria were used. The data were extracted into 2 primary categories, including challenges and facilitators to controlling pediculosis, each with several subcategories as follows: 1) economic-political aspects; 2) family factors; 3) social-cultural elements; 4) personal and mental issues; 5) geographical position of the investigated region; 6) school and education factors; and 7) factors related to medications and therapy. There were 2 types of facilitators: 1) informative factors and 2) social-cultural variables. According to the findings, pediculosis prevention, control, and treatment necessitate multifaceted and multi-level intervention. Some solutions must be addressed at the personal-psychological, familial, political-economic, geographical, and informational levels, as well as school-related concerns, social stigma elimination, and evaluation of cultural components of the issue at the social level.

Staying Ahead of Head Lice: Pediculosis Treatment Updates.

Pediculosis (head lice) infections are one of the more sensitive issues that may involve the school nurse. In the 3- to 11-year-old age group in the United States, head lice infections are common and can elicit anxiety in students, parents, and school personnel. Head lice do not transmit any communicable diseases and therefore exclusion from school and "no nit" policies are not warranted. Treatment and management for head lice include a range of over-the-counter products and prescription topical and oral medications. Nonpharmacologic and alternative treatments do exist; however, many do not have established efficacy studies, and some can be costly. The school nurse plays an integral role in providing education related to treatment and environmental recommendations for families affected by head lice. Through this education, the nurse can also reduce the stigma and anxiety many feel around the subject of head lice infections.

Infestations, Bites, and Insect Repellents.

Infestations and arthropod bite reactions in children are common reasons for presentation to pediatric health care providers. Infestations in children include head lice, scabies, and other mites. Fleas and bed bugs are common causes of bite reactions in children, and papular urticaria is a chronic, recurrent eruption resulting from delayed hypersensitivity to a variety of insect bites. Both infestations and bite reactions may result in severe pruritus with associated sleep disturbance and can be a source of significant distress for patients and families. In this review, we discuss infestations and bite reactions affecting pediatric patients, along with the approach to treatment and prevention of these conditions. [Pediatr Ann. 2020;49(3):e124-e131.].

Update on treatments for head lice.

Head lice infestation is common, and mainly affects children of primary school age. Treatments include conventional chemical insecticides; fine tooth louse combs; and fluid preparations that work by a physical rather than chemical mode of action. However, each of these fails to eradicate head lice in some patients. Other disadvantages include the long contact time required for certain preparations e.g. 8 hours and the time commitment for combing regimens. Isopropyl myristate 50% in cyclomethicone solution (Full Marks Solution - SSL International) is a new fluid treatment with a physical mode of action that uses a 10-minute contact time. Here, we consider this product in the context of updating advice we gave in 2007 on treatments for head lice.

Pediculus humanus capitis: an update.

Head lice infestation, or pediculosis capitis, caused by Pediculus humanus capitis, is a common health concern. In the US, where pediculosis capitis is the most prevalent parasitic infestation of children, 6 to 12 million people are affected every year. Pediculosis capitis remains confined to the scalp. Scalp pruritus is the cardinal symptom, although patients with lice can be asymptomatic. Pruritus with impetiginization should prompt the physician to look for lice or viable nits. All close contacts should be examined. Treatment directed at killing the lice and the ova should be considered only if active lice or viable eggs are observed. The three fundamental effective treatment options for head lice are topical pediculicides, wet combing, and oral therapy. Spraying or fogging a home with insecticides or pediculicides is not recommended.

Does dimeticone clear head lice?

Head lice infestation is common and mainly affects children of primary school age. Treatments include licensed topical preparations containing conventional chemical insecticides and medical devices. Each of these fail to eradicate head lice in some patients and resistance is a problem with chemical insecticides. Dimeticone 4% lotion (Hedrin - Thornton & Ross) is a new treatment licensed "for the eradication of head lice infestations". Here we consider its place in the context of other options.