Head lice on pillows, and strategies to make a small risk even less

Comparing the efficacy of three methods of permethrin application in pediculosis capitis: A randomized clinical trial

BACKGROUND

Pediculosis capitis, also known as head lice, is a common problem that affects individuals of different socio-economic backgrounds. Permethrin is generally considered the first-line treatment option for head lice.

AIMS

The objective of this study was to evaluate and compare the therapeutic effects of three different methods of permethrin treatment for head lice.

METHOD

A parallel, randomized clinical trial was conducted on 157 patients with head lice. The participants underwent eye examination and dry combing by a trained professional. The subjects were randomly divided into three groups and treated with one of the three methods of permethrin application: permethrin shampoo for 10 min, permethrin shampoo for 1 h, or permethrin cream for 10 min on a weekly basis for 3 weeks.

RESULTS

Of the 157 participants, 154 completed the study. The group treated with permethrin shampoo for 1 h had the shortest average time for eradication of lice at 1.226 ± 0.422 weeks, which was significantly lower than the other two groups. Additionally, the 1-h permethrin shampoo group had the lowest time for scalp itching of 2.15 ± 0.632 weeks, which was significantly lower than the other two groups. Moreover, the rate of lice eradication in the first week was significantly higher in the 1-h permethrin shampoo group.

CONCLUSION

The results of this study suggest that the use of 1% permethrin shampoo for 1 h is more effective in eradicating head lice within the first week of treatment and in relieving scalp itching during the second week.

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.

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.

Lice Update: Management and Treatment in the Home

Lice infestation is a common health issue affecting 6 to 12 million school-age children in the United States each year, impacting all members of the household. The home care nurse can be a valuable resource in the management of lice in the home and can assist the family in understanding the various myths and misconceptions about lice. This article provides an overview of lice management, including identification and treatment of a lice infestation as well as recommendations for environmental control strategies in the home. It includes an overview of the various over-the-counter and prescription treatment options and highlights the social stigma that is often associated with a lice infestation.

Do drowning and anoxia kill head lice?

Chemical, physical, and mechanical methods are used to control human lice. Attempts have been made to eradicate head lice Pediculus humanus capitis by hot air, soaking in various fluids or asphyxiation using occlusive treatments. In this study, we assessed the maximum time that head lice can survive anoxia (oxygen deprivation) and their ability to survive prolonged water immersion. We also observed the ingress of fluids across louse tracheae and spiracle characteristics contrasting with those described in the literature. We showed that 100% of lice can withstand 8 h of anoxia and 12.2% survived 14 h of anoxia; survival was 48.9% in the untreated control group at 14 h. However, all lice had died following 16 h of anoxia. In contrast, the survival rate of water-immersed lice was significantly higher when compared with non-immersed lice after 6 h (100% vs. 76.6%, p = 0.0037), and 24 h (50.9% vs. 15.9%, p = 0.0003). Although water-immersed lice did not close their spiracles, water did not penetrate into the respiratory system. In contrast, immersion in colored dimeticone/cyclomethicone or colored ethanol resulted in penetration through the spiracles and spreading to the entire respiratory system within 30 min, leading to death in 100% of the lice.

Head lice infestations: A clinical update

Head lice (Pediculus humanus capitis) infestations are not a primary health hazard or a vector for disease, but they are a societal problem with substantial costs. Diagnosis of head lice infestation requires the detection of a living louse. Although pyrethrins and permethrin remain first-line treatments in Canada, isopropyl myristate/ST-cyclomethicone solution and dimeticone can be considered as second-line therapies when there is evidence of treatment failure.

Orientation of Head Lice on Human Hosts, and Consequences for Transmission of Pediculosis: The Head Lice Movement Studies

We performed head lice movement studies to elucidate factors influencing orientation and movement of head lice. Studies included observation of lice movements on hand and forearm at different positions of the upper limb; movements exposed to unshaved and shaved forearm; and movements with and without antennae. In 57 of 60 (95.0%) observations while holding the hand down, lice moved proximal, and 3 (5%) distal. While holding the hand up, 37/60 (61.7%) moved proximal, and 23 (38.3%) distal (p < 0.0001). On the unshaved limb, 29/30 (96.7%) moved proximal, with clockwise movements in 26/30 (86.7%). After shaving, 9/30 (30%) walked proximal and 18 (60%) distal, with 12/30 (40%) clockwise movements. After antennectomy, while holding the hand up, 16/25 (64%) lice did not move, 1 (4%) walked proximal, and 8 (32%) distal. While handing the hand down, 17/25 (68%) did not move, 5 (20%) walked proximal, and 3 (12%) distal. Transmission of head lice may not only occur by head-to-head contact, but also via head-to-body contact, with movement to the head against gravitational pull. Surface factors of hand and forearm may be important in orientation for lice, in addition to gravity. Movement of lice against gravity is not governed by organs in the antennae.

Efficacy of Peer Education for Adopting Preventive Behaviors against Head Lice Infestation in Female Elementary School Students: A Randomised Controlled Trial

Background

Pediculosis is a common parasitic infestation in students worldwide, including Iran. This condition is more prevalent in populous and deprived communities with poor personal hygiene. This study sought to assess the efficacy of peer education for adopting preventive behaviors against pediculosis in female elementary school students based on the Health Belief Model (HBM).

Methods

A total of 179 female fifth grade students were selected using multistage random sampling and were randomly allocated to control and intervention groups. A standard questionnaire was designed and administered to collect baseline information. An educational intervention was then designed based on the conducted needs assessment. The educational program consisted of three sessions, held by peers for the intervention group. The questionnaire was re-administered one month after the intervention. Independent and paired t-test, Pearson’s correlation coefficient, and regression analysis were applied as appropriate.

Results

The two groups had no significant differences in the scores of knowledge, HBM constructs, or behavior before the intervention. After the intervention, however, the mean scores of all parameters significantly improved in the intervention group.

Conclusion

Peer education based on HBM is an effective strategy to promote preventive behaviors against pediculosis in among fifth grade female elementary school students in Iran.

Head Lice

BACKGROUND

Conflicting information about the proper treatment of head lice has given rise to uncertainty among patients and treating personnel. For example, the reported efficacy of permethrin fell from 97% in the 1990s to 30% in 2010.

METHODS

Review of the literature based on a selective search of PubMed.

RESULTS

In Germany, outbreaks of head lice mainly occur among 5- to 13-year-olds returning to school after the summer vacation. Nymphs hatch from eggs after an average of 8 days and become sexually mature lice over the ensuing 9 days. The main route of transmission is direct head-to-head contact; transmission via inanimate objects is of no relevance. Symptoms arise 4-6 weeks after an initial infestation; many affected persons have no symptoms at all. Wet combing is the most sensitive method of establishing the diagnosis and monitoring treatment. Resistance to neurotoxic pediculocidal drugs is increasing around the world. Dimethicones are the treatment of choice, with 97% efficacy. Outbreaks must be managed with the synchronous treatment of all infested persons to break the chain of infestation. If the agent used is not ovicidal, the treatment must be repeated in 8-10 days and sometimes in a further 7 days as well.

CONCLUSION

Outbreaks of head lice can be successfully terminated by synchronous treatment with ovicidal dimethicones.

A Lousy Reason for Surgery Cancellations

Cancellation of surgery has significant adverse impact on patients, health care providers, and their associated facilities. Although head lice infestation has not been shown to be associated with adverse surgical outcomes, it often prompts case cancellation by surgical and anesthesia personnel. The purpose of our study was to evaluate the extent and impact of surgery cancellations due to head lice infestation. In our study, a total of 9 patients were cancelled over a 3-year period. Although there is no direct evidence to show that head lice infestation poses a risk to surgical outcomes, the possibility of underlying secondary bacterial infection at the skin excoriation site is often the concern in these patients. This study offers the first investigation into the impact of head lice infections on operating room cancellations, which may prove to be a potential source of intervention to prevent cancellations.

Head lice

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2010 clinical report on head lice was published by the American Academy of Pediatrics, newer medications have been approved for the treatment of head lice. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting.

Head lice

Head lice infestation is associated with limited morbidity but causes a high level of anxiety among parents of school-aged children. Since the 2002 clinical report on head lice was published by the American Academy of Pediatrics, patterns of resistance to products available over-the-counter and by prescription have changed, and additional mechanical means of removing head lice have been explored. This revised clinical report clarifies current diagnosis and treatment protocols and provides guidance for the management of children with head lice in the school setting.

Fomite transmission in head lice

Control of various infestations requires an accurate understanding of transmission. After thousands of years of lice infestation, scientific documentation of indirect contact transmission has been substantiated. Lice can be transferred in the egg, instar, and adult stages. Lice have now been shown in the laboratory to be readily dislodged by air movements such as blow-drying one's hair, combing, and toweling. Moreover, passive transfer to adjoining fabric is also frequently observed. Louse transmission by fomites occurs more frequently than has been commonly believed. Close proximity suffices to increase the likeliness of a new infestation. Thus louse control measures should take account of fomite transmission and include screening of all individuals within an infested person's immediate circle of contact, laundering of everything within the infested individuals' bed or quarantining of such material for 10 days, thorough vacuuming of floors, carpets, upholstery, with a standard vacuum cleaner.

Therapy for head lice based on life cycle, resistance, and safety considerations

The timing of head lice maturation most favorable to their survival in the presence of anti-lice agents is the maximum time as an ovum (12 days) and the shortest possible time of maturing from newly hatched nymph to egg-laying adult (8.5 days). Pediculicides that are not reliably ovicidal (pyrethroids and lindane) require 2 to 3 treatment cycles to eradicate lice. Ovicidal therapies (malathion) require 1 to 2 treatments. Treatment with an agent to which there is genetic resistance is unproductive. In the United States, lice have become increasingly resistant to pyrethroids and lindane but not to malathion. Treatment with malathion has favorable efficacy and safety profiles and enables the immediate, safe return to school. Nit combing can be performed adjunctively. No-nit policies should be rendered obsolete.

Efficacy of Machine Laundering to Eradicate Head Lice: Recommendations to Decontaminate Washable Clothes, Linens, and Fomites

The efficacy of machine laundering to eradicate head lice should be determined. Viable lice and nits were machine laundered using 3 washing programs (with water temperatures of 40 degrees C, 50 degrees C, and 60 degrees C), with and without detergent, and the results were compared with results for control lice and nits. A drying program was also used. Either washing done with a water temperature of at least 50 degrees C or drying is necessary to kill head lice and nits.

Safety and efficacy of pediculicides for head lice

Head lice infestation is a common and growing problem, primarily affecting school-aged children. There are growing numbers of treatment failures due to the emergence of treatment-resistant lice to the popular over-the-counter products that have been used for the past several decades. Resistance has also decreased the efficacy of lindane, a prescription pediculicide that has been commonly used for several generations. Malathion, recently reintroduced in the US as a prescription pediculicide, has been associated with some treatment resistance depending upon its formulation. Other insecticidal treatments, such as ivermectin, will have to be developed further, given the limited options presently available for the treatment of head lice. Given the number of anecdotal and market-driven reported studies on head lice, assessment of topical lice therapies requires standardised in vitro testing. Based on concerns about safety and decreasing efficacy due to resistance, a reassessment of the general topic of pediculicides for head lice is warranted.

Scabies, pediculosis, bedbugs, and stinkbugs: uncommon presentations

Parasitic agents determine some of the most common skin disorders. Although well known, they could present different manifestations or be modified by individual or external factors that make their diagnosis or treatment difficult. This review will discuss some of the most prevalent parasitic infections, scabies, and pediculosis and also mention reactions determined by contact with certain insects that, although rarely found, could induce important skin reactions.

Milben, Läuse und Flöhe

Ectoparasitoses or epizoonoses are skin disorders caused by animal parasites living on the body surface. Worldwide they are among the most frequent dermatoses, particularly in infancy and childhood. Distinguishing between conditions caused by permanent and temporary ectoparasites is important for the course and the required therapy. Permanent ectoparasites, such as scabies mite and head louse, spend all their life in or on the skin and have to be killed on the patient with suitable acaricides or pediculicides. In contrast, temporary ectoparasites, as animal mites or fleas, attack humans only for feeding. Symptomatic topical therapy is usually sufficient, eventually in combination with decontamination measures in the environment. This article summarizes skin conditions caused by mites, lice and fleas with special emphasis on distinctive features in children.

A simple treatment for head lice: dry-on, suffocation-based pediculicide

OBJECTIVES

The emergence of drug-resistant lice has created the need for new therapies. This study assesses a new method without neurotoxins, extensive household cleaning, or nit removal.

METHODS

One hundred thirty-three subjects participated in 2 open clinical trials. In the first trial, 93 subjects completed treatment using a nontoxic, dry-on, suffocation-based, pediculicide lotion, minimal household cleaning measures, and physical removal of the nits. In the second trial, 40 subjects completed treatment using an identical protocol except that the nits were not removed. Head lice infestation was defined as a wet combing test showing lice. Cure was defined as a wet combing test showing no lice, with an absence of symptoms. Subjects were contacted 6 months later, for assessment of their disease status.

RESULTS

Cure was achieved for 97% of the patients in the first trial and 95% in the second trial. Remission at the follow-up assessment was reported for 77 of 82 subjects (94%) in the first trial and 36 of 38 subjects (95%) in the second trial. There was no statistical difference in cure rates or remission rates between the protocols with and without nit removal. The overall cure rate was 96%, with a remission rate of 94%. There were no adverse effects.

CONCLUSIONS

Dry-on, suffocation-based, pediculicide lotion effectively treats head lice without neurotoxins, nit removal, or extensive house cleaning. These results are comparable or superior to the results previously reported for treatments with permethrin, pyrethrin, and malathion.

Arthropods in dermatology

Arthropods are important in medicine for a multitude of reasons. Their bites and stings may induce allergic reactions, ranging from annoying to life-threatening. Many arthropod products are also capable of inciting allergic responses in sensitized persons. In recent years, bites and stings have gained greater attention owing to increased concern about disease transmission. A common hypersensitivity response to arthropod bites, stings, and products is papular urticaria. This eruption occurs primarily in children, who eventually "outgrow" this disease, probably through desensitization after multiple arthropod exposures. Papular urticaria is most often caused by fleas or bedbugs, but virtually any arthropod is capable of inducing such a reaction. Two arthropod classes of medical importance are the Arachnida (spiders, scorpions, ticks, and mites) and the Insecta (lice, fleas, bedbugs, flies, bees, and ants). Animals in these two classes are probably responsible for more morbidity and mortality worldwide than are any other group of venomous creatures. In general, the diagnosis of arthropod bites and stings is dependent on maintenance of a high index of suspicion and familiarity with the arthropod fauna not only in one's region of practice, but also in the travel regions of one's patients. Learning objective At the completion of this learning activity, participants should be familiar with the clinical manifestations caused by a variety of arthropods as well as the treatment and possible sequelae of arthropod attacks.