Scabies and pediculosis

Secondary Bacterial Infections in Patients with Atopic Dermatitis or Other Common Dermatoses

Secondary bacterial infections of common dermatoses such as atopic dermatitis, ectoparasitosis, and varicella zoster virus infections are frequent, with Staphylococcus aureus and Streptococcus pyogenes being the bacteria most involved. There are also Gram-negative infections secondary to common dermatoses such as foot dyshidrotic eczema and tinea pedis. Factors favoring secondary bacterial infections in atopic dermatitis, ectoparasitosis, and varicella zoster virus infections mainly include an epidermal barrier alteration as well as itch. Mite-bacteria interaction is also involved in scabies and some environmental factors can promote Gram-negative bacterial infections of the feet. Furthermore, the bacterial ecology of these superinfections may depend on the geographical origin of the patients, especially in ectoparasitosis. Bacterial superinfections can also have different clinical aspects depending on the underlying dermatoses. Subsequently, the choice of class, course, and duration of antibiotic treatment depends on the severity of the infection and the suspected bacteria, primarily targeting S. aureus. Prevention of these secondary bacterial infections depends first and foremost on the management of the underlying skin disorder. At the same time, educating the patient on maintaining good skin hygiene and reporting changes in the primary lesions is crucial. In the case of recurrent secondary infections, decolonization of S. aureus is deemed necessary, particularly in atopic dermatitis.

Scabies in infants and children - a narrative review

Scabies is a human ectoparasitosis caused by Sarcoptes scabei var. hominis. World-wide around 300 million patients are affected. Infants and children have the highest incidence rates. Poverty and overcrowding are social factors contributing to a higher risk of transmission and treatment failure. The leading symptom of the infestation is itch. Complications are bacterial infections that are responsible for mortality. Diagnosis is clinical. Non-invasive imaging technologies like dermoscopy can be used. Polymerase chain reaction (PCR) is less sensitive and specific than microscopy of skin scrapings. Treatment of choice is topical permethrin 5%. Ivermectin is the only oral drug FDA-approved for scabies. It should be used in cases non-responsive to topical therapy and in case of high number of infested patients in addition to topical therapy. Pseudo-resistance to treatment is not uncommon. New drugs are on the horizon. What is Known: • Pruritus is the leading symptom causing sleep disturbances and scratching with the risk of secondary bacterial infections. • Treatment failure is related to inappropriate application of topical drugs and asymptomatic family members. What is New: • COVID-19 pandemic and migration are contributing to an increased incidence of scabies. • New compounds to treat scabies are on the horizon.

Spanish Academy of Dermatology and Venereology (AEDV) expert recommendations for the management of sexual transmitted parasitosis. Scabies, and pediculosis pubis

Sexually transmitted infections are communicable diseases where the pathogen is transmitted through sexual contact. The Sexually Transmitted Infections Working Group of the Spanish Academy of Dermatology and Venereology (AEDV) is engaged in the drafting of documents to guide dermatologists and health care personnel who treat Spanish patients with these infections. This document analyzes the epidemiological, clinical, therapeutic, and control characteristics of 2 sexually transmitted parasitosis: scabies due to Sarcoptes scabiei var. hominis, and pubic pediculosis due to Phthirus pubis. Both parasitoses share a sort of mixed spread through sexual and community transmission regardless of the route through which the infection was initially acquired. This specific feature creates particularities in the management and control of the infestation.

[Translated article] Spanish Academy of Dermatology and Venereology (AEDV) expert recommendations for the management of sexual transmitted parasitosis. Scabies, and pediculosis pubis

Sexually transmitted infections are communicable diseases where the pathogen is transmitted through sexual contact. The Sexually Transmitted Infections Working Group of the Spanish Academy of Dermatology and Venereology (AEDV) is engaged in the drafting of documents to guide dermatologists and health care personnel who treat Spanish patients with these infections. This document analyzes the epidemiological, clinical, therapeutic, and control characteristics of 2 sexually transmitted parasitosis: scabies due to Sarcoptes scabiei var. hominis, and pubic pediculosis due to Phthirus pubis. Both parasitoses share a sort of mixed spread through sexual and community transmission regardless of the route through which the infection was initially acquired. This specific feature creates particularities in the management and control of the infestation.

Scrotal nodular scabies

Scabies is a highly infectious parasitic skin disease, The most common lesions are solid and 2-3 mm in diameter (papules). Very few cases will develop into nodular scabies, and microscopy is frequently negative in patients with clinically diagnosed nodular scabies. The accuracy of microscopy depends on the expertise of the operator, particularly in finding burrows and extracting the relevant material.

Clinical and Epidemiological Characteristics of Patients Being Treated for Scabies in Spain: Opportunities for Improvement - A Multicenter Cross-Sectional CLINI-AEDV Study

BACKGROUND

Several studies support the hypothesis that scabies is on the rise in Spain. There are also concerns about the possible development of resistance to treatment and an increase in atypical presentations. The aims of this study were to describe the demographic and clinical characteristics of patients with scabies seen by dermatologists in Spain, to identify the possible emergence of atypical forms of scabies, and to explore the frequency of treatment failures and associated risk factors.

METHODS

We conducted an observational, cross-sectional, multicenter study of data collected prospectively in April and May 2023 using the CLINI-AEDVp platform created by the Spanish Academy of Dermatology and Venereology (AEDV).

RESULTS

Participating dermatologists from 31 hospitals in 15 of Spain's autonomous communities recorded 186 cases of active scabies (51% in women) during the study period. A diagnostic certainty level of A, B or C as per the International Alliance for the Control of Scabies Consensus Criteria was required for diagnosis. Overall, 92% of patients had typical scabies and 66% had already been treated with a scabicide for the current episode. Of the treated patients, only 36% had received and completed adequate treatment (including the simultaneous treatment of all household members) and 50% had not received clear written recommendations.

CONCLUSIONS

In a high proportion of the cases of scabies studied, the patient had already received treatment. In those cases, we observed several remediable shortcomings that could explain why some of these treatments had failed. Remedying these deficiencies should lead to better control of scabies and an improved assessment of the actual effectiveness of currently available scabicides.

[Translated article] Clinical and Epidemiological Characteristics of Patients Being Treated for Scabies in Spain: Opportunities for Improvement - A Multicenter Cross-Sectional CLINI-AEDV Study

BACKGROUND

Several studies support the hypothesis that scabies is on the rise in Spain. There are also concerns about the possible development of resistance to treatment and an increase in atypical presentations. The aims of this study were to describe the demographic and clinical characteristics of patients with scabies seen by dermatologists in Spain, to identify the possible emergence of atypical forms of scabies, and to explore the frequency of treatment failures and associated risk factors.

METHODS

We conducted an observational, cross-sectional, multicenter study of data collected prospectively in April and May 2023 using the CLINI-AEDVp platform created by the Spanish Academy of Dermatology and Venereology (AEDV).

RESULTS

Participating dermatologists from 31 hospitals in 15 of Spain's autonomous communities recorded 186 cases of active scabies (51% in women) during the study period. A diagnostic certainty level of A, B or C as per the International Alliance for the Control of Scabies Consensus Criteria was required for diagnosis. Overall, 92% of patients had clinical features of classic scabies and 66% had already been treated with a scabicide for the current episode. Of the treated patients, only 36% had received and completed adequate treatment (including the simultaneous treatment of all household members) and 50% had not received clear written recommendations.

CONCLUSIONS

In a high proportion of scabies cases, the patient has already received treatment. In those cases, we observe several remediable shortcomings that could explain why some of these treatments fail. Remedying these deficiencies should lead to better control of scabies and an improved assessment of the actual effectiveness of currently available scabicides.

Case report: Head lice in the eyelashes

Purpose

Head lice infection of the eyelashes and adjacent eyelids is extremely rare. In this case report we present a child with head lice infection of the eyelashes.

Observations

A 3-year-old boy presented to the ophthalmology department with a chief complaint of itching and visible abnormal secretions of the upper eyelashes in the right eye for more than 1 week. On ocular examination, a large number of nits and brown secretions were tightly adhered to the root of the upper eyelashes of the right eye, and translucent parasites crept slowly along the eyelashes, without impairment of vision. A few of the parasites and nits were further viewed with a microscope and were identified as head lice.

Conclusions and Importance

This case suggests that ophthalmologists should not only consider common inflammation and allergies, but also be alert to parasitic infections when treating patients with ocular itching and abnormal secretions.

The Impact of the COVID-19 Pandemic on the Prevalence of Head Lice Infestation among Children Attending Schools and Kindergartens in Poland

Pediculosis capitis predominantly affects child populations. During the COVID-19 pandemic, various types of social limitations such as social isolation and limitations on educational facilities' functionalities were introduced worldwide, including in Poland. The impact of these pandemic restrictions on the prevalence of pediculosis capitis has not been extensively investigated so far. Existing data on this topic are limited mainly to indirect evaluation methods, such as online surveys or Internet analysis. In this study, we directly examined a cohort of over five thousand children to assess the influence of COVID-19 pandemic restrictions on the prevalence of head lice infestation among school and kindergarten attendees in Poland. Our findings demonstrate that the restrictions imposed during the COVID-19 pandemic led to a decrease in the number of children infested with head lice compared to pre-pandemic data. These results confirm that head lice infestations remain an ongoing epidemiological concern and warrant continued monitoring.

Lice and lice-borne diseases in humans in Africa: a narrative review

Lice are host-specific insects. Human lice include Pediculus humanus humanus (body lice) which are known to be vectors of serious human bacterial infectious diseases including epidemic typhus, relapsing fever, trench fever and plague; Pediculus humanus capitis (head lice) that frequently affect children; and Pthirus pubis, commonly known as crab lice. In Africa, human infections transmitted by lice remained poorly known and therefore, underestimated, perhaps due to the lack of diagnostic tools and professional knowledge. In this paper we review current knowledge of the microorganisms identified in human lice in the continent of Africa, in order to alert health professionals to the importance of recognising the risk of lice-related diseases.

A Rare Case of Anemia Secondary to Lice Infestation

Lice are parasitic infections that can infect humans and survive by consuming host blood. They are most commonly associated with a lack of hygiene and occur most commonly in school-age children, homeless populations, and densely populated areas. Lice infections can potentially lead to vector-containing illness and are rarely complicated by acute blood loss anemia. These side effects, while exceedingly rare, are often very significant and potentially life-threatening. Here we present a rare case of severe anemia found in a patient with chronic lice colonization. We hope our findings will broaden the differential for acute anemias and raise awareness of lice infection as a possible cause of acute anemia.

Human pediculosis, a global public health problem

Background

Human pediculosis is caused by hematophagous lice, which are transmitted between individuals via direct and/or indirect contact. Despite the public health importance of louse infestation, information concerning the global burden of pediculosis and the epidemiological landscape of louse-borne diseases is limited. The aim of this review was to summarize the biology, epidemiology, diagnosis, and control of lice infestation in humans. We also discussed the latest advances in molecular taxonomy and molecular genetics of lice.

Methods

We searched five electronic bibliographic databases (PubMed, ScienceDirect, CNKI, VIP Chinese Journal Database, and Wanfang Data) and followed a standard approach for conducting scoping reviews to identify studies on various aspects of human lice. Relevant information reported in the identified studies were collated, categorized, and summarized.

Results

A total of 282 studies were eligible for the final review. Human pediculosis remains a public health issue affecting millions of people worldwide. Emerging evidence suggests that head lice and body lice should be considered conspecific, with different genotypes and ecotypes. Phylogenetic analysis based on mitochondrial (mt) cytb gene sequences identified six distinct clades of lice worldwide. In addition to the direct effect on human health, lice can serve as vectors of disease-causing pathogens. The use of insecticides plays a crucial role in the treatment and prevention of louse infestation. Genome sequencing has advanced our knowledge of the genetic structure and evolutionary biology of human lice.

Conclusions

Human pediculosis is a public health problem affecting millions of people worldwide, particularly in developing countries. More progress can be made if emphasis is placed on the use of emerging omics technologies to elucidate the mechanisms that underpin the physiological, ecological, and evolutionary aspects of lice.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-00986-w.

A 12-Year-old Girl With Chronic Pediculosis Infestation Presenting With Severe Iron Deficiency Anemia

Iron deficiency is the leading etiology of anemia worldwide. Excessive cow's milk intake and menorrhagia are the most common etiologies in the pediatric population in the United States, with parasitic infections a more common cause in lower-resource countries. Here we present a case of a 12-year-old female in the midwestern United States with severe iron deficiency anemia (hemoglobin 4.7 g/dL) and chronic pediculosis infestation. Anemia resolved with transfusion, iron supplementation, and eradication of the parasite. We believe this is the only reported case of a child in the United States with severe iron deficiency anemia secondary to chronic severe lice infestation.

Bullous Scabies in an Immunocompromised Host

A 40-year-old woman with a history of poorly controlled HIV presented to a district referral hospital in rural Botswana for a generalized skin rash of several months duration. The highly pruritic rash predominantly involved her hands and feet and was associated with bullae that were present for days at a time before rupturing without drainage or discharge. The patient endorsed night sweats, periodic fevers, occasional cough productive of blood-tinged sputum, fatigue, and weight loss. On admission, CD4 count was 46 cells/mm³ and viral load was >750000 copies/mL. Pulmonary tuberculosis testing via sputum was negative twice. A blood count demonstrated eosinophilia. Oral acyclovir was started empirically for disseminated herpes virus infection, with topical beclomethasone and intravenous antibiotics for possible superinfected bullous dermatosis. With inadequate response to treatment, a skin biopsy was obtained and microscopic examination demonstrated scabies mites. The absence of skin burrows, the presence of bullae, and working in a low-resource setting without direct access to microscopic examination delayed diagnosis. The patient was initiated on topical permethrin. Oral ivermectin was not available in country and was obtained from overseas shipment, delaying treatment initiation. Drastic improvement was seen after the patient initiated ivermectin. A local nurse in the patient's village visited her community and found multiple individuals with active scabies infection. The patient's discharge was delayed until these community members were treated successfully with topical permethrin. This case describes an atypical presentation of scabies in an under-resourced setting, demonstrating unique diagnostic, therapeutic, and public health challenges.

Crusted scabies in children in France: a series of 20 cases

To evaluate the risk factors for crusted scabies in children in France. The retrospective multicenter study, conducted in France, of children (aged < 18 years) with profuse and/or crusted scabies confirmed by dermoscopy and/or microscopy. Data were obtained using a standardized questionnaire. We included 20 children. The mean age was 4.5 years, and 70% of the patients were girls. Their medical history revealed a neurological pathology (agenesis of the corpus callosum; n = 1, 5.0%), prematurity (n = 1, 5.0%), Down syndrome (n = 1, 5.0%), atopic dermatitis (n = 2, 10%), and asthma (n = 2, 10.0%). Fifteen (75.0%) children were treated with steroids before being diagnosed with scabies: 12 (60.0%) with topical steroids, one (5.0%) with a systemic steroid, and two (10.0%) with inhaled steroids. One child (5.0%) lived in a precarious environment. The mean duration of pruritus was 3.4 months, and that of the skin lesions was 3.1 months. The most commonly affected areas for crusted scabies were the palms/hands (66.7%) and the armpits (33.3%). Thirteen children (65.0%) were hospitalized, 14 (70.0%) were treated with ivermectin and all received topical treatments; 85.7% were cured within an average of 38 days, but one child had a relapse 3 months later in the form of common scabies.Conclusion: The main risk factor for developing crusted scabies in France was the misdiagnosis and the use of corticosteroids, especially topical forms typically used in "healthy" children. Management of the children was effective and similar to that used in adults. What is Known: • Crusted scabies is an extremely contagious disease which is rarely reported in infancy, especially in healthy children. • The main risk factors include immunosuppression, physical debilitation, and intellectual disability. What is New: • The main risk factor of severe scabies in this study was delayed diagnosis associated with the use of topical or systemic corticosteroids. • The treatment was successful in 85.7% of cases, and 65% of children needed to be hospitalized.

HTLV-1 and Co-infections

Human T lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes lifelong T-cell infection in humans, impacting the host immune response. This virus causes a range of clinical manifestations, from inflammatory conditions, including neuronal damage (HTLV-1 associated myelopathy, HAM) to life-threatening leukemia (adult T-cell leukemia, ATL). Human T lymphotropic virus type 1 is also associated with increased risk of all-cause mortality, but the mechanisms remain unclear. As a blood-borne and sexually transmitted infection (STI), HTLV-1 shares transmission routes to many other pathogens and although it has worldwide distribution, it affects mainly those in low- and middle-income tropical areas, where the prevalence of other infectious agents is high. These factors contribute to a high incidence of co-infections in people living with HTLV-1 (PLHTLV). This comprehensive review addresses the impact of HTLV-1 on several co-infections and vice-versa. There is evidence of higher rates of HTLV-1 infection in association with other blood borne (HCV, HBV) and sexually transmitted (Syphilis, Chlamydia, HPV, HSV) infections but whether this represents increased susceptibility or opportunity is unclear. Higher frequency of Mycobacterium tuberculosis (MTb) and Mycobacterium leprae (M. leprae) is observed in PLHTLV. Reports of opportunistic infections and high frequency of crusted scabies in patients with HTLV-1 points to immune impairment in those individuals. Human T lymphotropic virus type 1 may influence the persistence of pathogens, exemplified by the higher rates of Schistosoma mansoni and Strongyloides stercoralis (St. stercoralis) treatment failure observed in PLHTLV. This retrovirus is also associated with increased tuberculosis (TB) severity with some evidence pointing to a deleterious impact on leprosy outcome as well. These findings are supported by immune alterations observed in those co-infected individuals. Although the role of HTLV-1 in HCV outcome is debatable, most data indicate that HTLV may negatively impact the clinical course of hepatitis C. Co-infections may also influence the risk of developing HTLV-1 associated disease, but data are still limited. The impact of HTLV-1 on the response to more common infections, might contribute to the increased mortality rate of HTLV-1. Large scale prospective controlled studies on the prevalence and impact of HTLV-1 in co-infections and vice-versa are needed. Human T lymphotropic virus type 1 impact in public health is broad. Measures to increase awareness and to prevent new infections are needed.

Dermatology on the Global Stage: The role of dermatologists in international health advocacy and COVID-19 research

Background

Over the last decade, there has been a surge in interest and funding for global health dermatology. Skin conditions are now recognized as the fourth leading cause of nonfatal disease burden worldwide in disability-adjusted life years. Dermatologists are uniquely positioned within global health because skin conditions are often the presenting sign of severe illnesses, such as neglected tropical diseases and COVID-19.

Methods

We review four major areas of work by dermatologists within global health: i) characterization of global burden of skin disease, ii) advocacy for dermatologic therapies on the World Health Organization's Model List of Essential Medicines, iii) advancements in global programming for skin-related tropical diseases, and iv) the role of dermatologists during the COVID-19 pandemic. For each area of work, the significance and impact on the health of women and girls is briefly highlighted.

Results

Dermatologists have led the efforts to quantify and evaluate the global burden of skin disease, the burden of which is disproportionately shared by women. The dermatology community has also championed global efforts to eliminate skin-related neglected tropical diseases, such as scabies. Through national and international policy advocacy, dermatologists have pushed for more dermatologic therapies in the World Health Organization's Model List of Essential Medicines, helping to secure better care for patients with skin disease throughout the world. Since 2020, the dermatology community has worked collaboratively in the fight against COVID-19, establishing a worldwide registry for cutaneous manifestations of SARS-CoV-2 and pursuing research that has allowed colleagues in the house of medicine to better understand this landmark disease.

Conclusion

Through the study and promotion of global health, dermatologists have an important role in the house of medicine.

Risk factors for scabies treatment resistance: a retrospective cohort study

BACKGROUND

In order to successfully treat scabies and to prevent its spread, it is important to identify the factors that can influence the outcome of scabies treatment.

OBJECTIVES

This study was designed to evaluate the risk factors associated with treatment resistance scabies during use of an effective topical medication.

METHODS

A retrospective cohort study was performed in patients with scabies infestations confirmed by potassium hydroxide (KOH) examinations. Patient characteristics, clinical features and treatment history were collected. The treatment resistance group included patients with persistent scabies infestations for more than 28 days after initiation of antiscabies treatment with 5% permethrin cream.

RESULTS

In total, 138 patients with scabies infestations treated between January 2017 and December 2020 were included in this study. Of these, 100 (72.5%) patients were treated successfully, while 38 (27.5%) patients experienced treatment resistance. In the univariable analysis, risk factors for treatment resistance scabies included impaired cognitive function (OR = 2.66, 95% CI, 1.15-6.14), limited mobility (OR = 2.97, 95% CI, 1.30-6.83), inpatient status (vs. outpatient, OR = 3.3, 95% CI, 1.28-8.54), topical steroid use before diagnosis (OR = 3.52, 95% CI, 1.61-7.81), systemic steroid use before diagnosis (OR = 3.57, 95% CI, 1.26-10.34) and a positive KOH exam after the first treatment (OR = 7.25, 95% CI, 3.24-17.11). In the multivariable analysis, limited mobility (OR = 3.46, 95% CI, 1.02-12.11) and topical steroid use before diagnosis (OR = 3.65, 95% CI, 1.41-9.75) were significant predictive factors for treatment resistance scabies.

CONCLUSIONS

Scabies patients with limited mobility and topical steroid use before diagnosis are at high risk of treatment resistance. Dermatologists should take these findings into consideration when treating patients with scabies infestations.

Skin Diseases and their Treatment Strategies in Sub-Saharan African Regions

BACKGROUND

In the rural areas of sub-Saharan African regions, skin diseases are so common. Due to which the population of the sub-Saharan region suffers from different types of skin disorders. In these regions, many treatment options are not available for the treatment of skin disease.

AIM

The current study aims to discuss various skin diseases and their treatment strategies specifically in sub-Saharan African regions.

METHOD

Extensive literature survey was carried out by using scopus, science direct, elsevier, google scholar and bentham science databases.

RESULT AND DISCUSSION

It was demonstrated from the literature surveys that different effective techniques are used in the management of skin disease. In the result, it was shown that the condition of the disease is at a dangerous level which must be controlled.

CONCLUSION

It is concluded from the manuscript that the skin disorder in the sub-Saharan region is at a very dangerous level. The research must be done to develop a better understanding of the disease and its treatment.

Crusted Scabies Infection in the Setting of Chronic Steroid and Omalizumab Use

Scabies infection is a very common skin disease that occurs due to infestation with the Sarcoptes scabei mite. Typically, it results in intensely pruritic papules and excoriations in the webs of the hand, groin, or axilla, and remains limited in its spread. In rare cases, the disease can become diffuse and progress to crusted or nodular subtypes. Here, we report the case of crusted scabies infestation in a 69-year-old male who presented with a diffuse pruritic, erythematous, and petechial rash. His medical history was significant for severe idiopathic urticaria treated with omalizumab. Before starting omalizumab, the patient was self-medicating for several months with corticosteroids obtained through his veterinary practice to alleviate symptoms. His presentation was complicated by immune thrombocytopenic purpura and muscle weakness, likely secondary to omalizumab and corticosteroid use, respectively. The patient underwent an extensive rheumatologic workup until skin biopsy confirmed the underlying etiology as crusted scabies infestation. He was treated with ivermectin and weekly 5% permethrin skin cream with great improvement of his rash; however, unfortunately, he succumbed to bacterial sepsis. Scabies infestation can masquerade as a manifestation of other systemic diseases and is often misdiagnosed. As this case illustrates, initial misdiagnosis and subsequent treatment with immunosuppressive drug regimens can cause preventable, but potentially fatal, concomitant superinfections.

Bioactive Compounds as Potential Agents for Sexually Transmitted Diseases Management: A Review to Explore Molecular Mechanisms of Action

Sexually transmitted diseases (STDs) are produced by pathogens like bacteria, fungi, parasites, and viruses, and may generate severe health problems such as cancer, ulcers, and even problems in the newborn. This narrative review aims to present updated information about the use of natural bioactive compounds for the prevention and treatment of sexually transmitted infections. A search of the literature was performed using databases and search engines such as PubMed, Scopus, Google Scholar and Science Direct. From the pharmacotherapeutic management point of view, any strategies for prevention should contain medical approaches. The bioactive compounds obtained from natural products have shown biological effects against different microorganisms for the treatment of these diseases. The main results showed antimicrobial, antiprotozoal, antifungal and antiviral effects such as HIV. Also, the molecular mechanisms, signalling pathways and action targets of natural compounds were highlighted, thus justifying bacterial and antifungal inhibition, apoptosis or reduction of viral replication. From the data of our study, we can conclude that natural compounds may be a significant source for adjuvant drugs / complementary therapies in the treatment of STDs. With all these benefits, the future must conduct extensive clinical trials and the development of pharmaceutical nanotechnologies for a greater therapeutic effect.

Current Use of Ivermectin in Dermatology, Tropical Medicine, and COVID-19: An Update on Pharmacology, Uses, Proven and Varied Proposed Mechanistic Action

Ivermectin is a broad-spectrum antiparasitic drug with anti-inflammatory, anti-viral, anti-bacterial, and anti-tumor effects. In this review, we discuss the history, pharmacology, multimodal actions, indications in dermatology and tropical medicine, therapeutic and prophylactic use of ivermectin in COVID-19, safety, adverse effects, special considerations, and drug interactions of ivermectin.

Scabies itch: an update on neuroimmune interactions and novel targets

Frequently described as 'the worst itch' one can ever experience scabies itch is the hallmark of Sarcoptes scabiei mite infestation. Notably, the itchiness often persists for weeks despite scabicides therapy. The mechanism of scabies itch is not yet fully understood, and effective treatment modalities are still missing which can severely affect the quality of life. The aim of this review is to provide an overview of the scope of itch in scabies and highlight candidate mechanisms underlying this itch. We herein discuss scabies itch, with a focus on the nature, candidate underlying mechanisms and treatment options. We also synthesize this information with current understanding of the mechanisms contributing to non-histaminergic itch in other conditions. Itch is a major problem in scabies and can lead to grave consequences. We provide the latest insights on host-mite interaction, secondary microbial infection and neural sensitization with special emphasis on keratinocytes and mast cells to better understand the mechanism of itch in scabies. Also, the most relevant current modalities remaining under investigation that possess promising perspectives for scabies itch (i.e. protease-activated receptor-2 (PAR-2) inhibitor, Mas-related G protein-coupled receptor X2 (MRGPRX2) antagonist) are discussed. Greater understanding of these diverse mechanisms may provide a rational basis for the development of improved and targeted approaches to control itch in individuals with scabies.

First Description of the Composition and the Functional Capabilities of the Skin Microbial Community Accompanying Severe Scabies Infestation in Humans

Epidemiological studies link Sarcoptes scabiei infection and impetigo. Scabies mites can promote Streptococcus pyogenes (Group A Streptococcus) and Staphylococcus aureus infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. However, little is known about the composition and the function of the scabies-associated microbiota. Here, high-throughput whole-metagenome sequencing was used to explore the scabies-associated microbiome. Scabies mites including their immediate microenvironments were isolated from two patients with severe scabies in Northern Australia. Two ~45–50 million paired-end reads Illumina libraries were generated of which ~2 (5.1%) and 0.7 million (1.3%) microbial reads were filtered out by mapping to human (hg19) and mite draft genomes. Taxonomic profiling revealed a microbial community dominated by the phylum Firmicutes (A: 79% and B: 59%) and genera that comprise Streptococcus, Staphylococcus, Acinetobacter, and Corynebacterium. Assembly of the metagenome reads resulted in genome bins representing reference genomes of Acinetobacter baumannii, Streptococcus dysgalactiae (Group C/G), Proteus mirablis and Staphylococcus aureus. The contigs contained genes relevant to pathogenicity and antibiotics resistance. Confocal microscopy of a patient skin sample confirmed A. baumannii, Streptococci and S. aureus in scabies mite gut and faeces and the surrounding skin. The study provides fundamental evidence for the association of opportunistic pathogens with scabies infection.

Effectiveness and tolerability of a squalane and dimethicone-based treatment for head lice

Head lice (Pediculus humanus capitis) are worldwide obligate human ectoparasites, with high implications in pediatrics. In Europe, first-line topical neurotoxic insecticidal therapeutic strategies are being replaced by topical physically acting agents as the first-choice treatment. Safety of the active ingredients and high efficacy in a one-time single-dose treatment with a brief treatment application time are key issues for consumer use and effective compliance. The aim of this study was to assess the in vitro efficacy of a newly developed squalane and dimethicone-based pediculicidal formula, against motile head lice and eggs after 2 and 5 min immersion in the product, as well as its skin tolerance and acceptability under dermatological and pediatric expert control in children with atopic skin. The results indicate that at both time points, 100% mortality rate of head lice crawling stages and late-stage eggs was achieved. The formula was well tolerated and suitable for children with atopic skin from 12 months of age. Showing high in vitro efficacy and good skin acceptability, this solution is presented as a new safe alternative therapy for treatment of head lice infestations.

Paediatrics: how to manage scabies

This narrative review addresses scabies, a highly contagious, pruritic infestation of the skin caused by the mite Sarcoptes scabiei var hominis. Scabies is a common disorder that has a prevalence worldwide estimated to be between 200 and 300 million cases per year. Infestation is of greatest concern in children, the elderly, immunocompromised people and resource-poor endemic populations at risk of chronic complications. A diagnosis of scabies involves a clinical suspicion, a detailed targeted history, clinical examination and contact tracing. Dermoscopy and microscopy, where available, is confirmatory. Due to its infectivity and transmissibility, the management for scabies requires a multimodal approach: topical antiscabetic agents are the first line for most cases of childhood classic scabies and their contacts, which must also be identified and treated to prevent treatment failure and reacquisition. Environmental strategies to control fomite-related reinfestation are also recommended. Oral ivermectin, where available, is reserved for use in high-risk cases in children or in mass drug administration programmes in endemic communities. The prevention of downstream complications of scabies includes surveillance, early identification and prompt treatment for secondary bacterial infections, often superficial but can be serious and invasive with associated chronic morbidity and mortality. Post-scabetic itch and psychosocial stigma are typical sequelae of the scabies mite infestation. The early identification of patients with scabies and treatment of their contacts reduces community transmission. Although time consuming and labour intensive for caregivers, the implementation of appropriate treatment strategies usually results in prompt cure for the child and their contacts. Here, we provide a summary of treatments and recommendations for the management of paediatric scabies.

A dermoscopic study of cutaneous myiasis: other findings

BACKGROUND

Myiasis is a cutaneous infestation by the larvae of dipterous flies. It can be furuncular/nodular, papular, or pustular. Diagnosis of cutaneous myiasis depends mainly on clinical examination especially for the nodular form. The latter two forms can present diagnostic difficulties. Dermoscopy has been reported to be helpful. This report illustrates some of the dermoscopic features of this condition.

METHODS

The history, clinical findings, and dermoscopic findings of 15 affected individuals were documented.

RESULTS

Dermoscopy in all patients showed the posterior end of larvae (creamy-white bodies and respiratory spiracles resembling birds' legs with digitated feet). Larval motility and bubbles were noticed in 15 and 10 of patients, respectively. Skin surrounding the larvae showed hypopigmentation in 11 patients and an increase in dilated capillaries in 13.

CONCLUSIONS

Dermoscopy can facilitate the diagnosis of myiasis particularly of the papular and pustular forms.

Intervention protocol to improve scabies control in enclosed communities: a case report

OBJECTIVES

To describe patients with scabies in a prison setting. Document what type of treatment was carried out. Prepare an intervention protocol to improve scabies control in the Penitentiary Center.

MATERIAL AND METHOD

All cases of scabies diagnosed in the Youth Detention Centre (La Roca del Vallès, Barcelona) between November 2018 and November 2019 were recorded. The treatment used was recorded. Bibliographical research on the protocols and treatment guidelines was carried out for community-acquired scabies.

RESULTS

The study was performed with 762 inmates, of whom 61 patients were diagnosed with scabies. 39 patients' pathologies were detected at the time of admission to the center, 11 cases were diagnosed in the first 6 weeks after entering the prison, coinciding with the incubation period of the disease. Finally, 11 more were diagnosed when they had already been in prison for more than 6 weeks and therefore could be infected cases within the center. This parasitosis was detected mainly in inmates of North African origin, 14.7% of Algerian inmates and 14.2% of Moroccan inmates presented this pathology, compared to 1.6% among Spanish prisoners. All 61 patients were treated with permethrin and 8 cases had to repeat the treatment cycle due to apparent therapeutic failure. Research literature indicates that oral ivermectin should be the drug of first choice for the treatment of scabies in prison.

DISCUSSION

The high incidence of scabies cases detected in prison led us to carry out a bibliographic review that brought about changes in the treatment protocol that may be of interest for the control of the disease in closed communities.

The Incidence of Scabies and Head Lice and Their Associated Risk Factors among Displaced People in Cham Mishko Camp, Zakho City, Duhok Province, Iraq

This study was conducted to estimate the incidence and the effects of associated risk factors of scabies and head lice on displaced people in Cham Mishko camp, Zakho city, Duhok Province, Iraq. The study included 1300 internally displaced people (IDPs) who visited the dermatology clinic and health care center in Cham Mishko camp from January 2018 to December 2019. Participants' bio-information was collected on special questionnaire form after receiving permission from the camp's health authorities and verbal consent from the participants. Monthly weather data were collected from Duhok Directorate of Meteorology and Seismology. The total rate of ectoparasites was 81.2% (45% for scabies and 36.2% for head lice). Ages from 1-10, 21-30, and 31-40 years showed the highest rates with scabies (48.1%, 46.7% and 46.1%, respectively), while the highest rates of head pediculosis were at ages from 1-10 and 11-20 years (40% and 36.6%, respectively). Scabies rate was slightly higher in males than females (46.6% vs. 43.4%), while the rate of head pediculosis was significantly higher in females than males (58.2% vs. 13.9%). Families with more than ten people showed the highest rates of scabies and head pediculosis (49.5% and 74.5%). Scabies was more common in cold months than in summer while head pediculosis was more common in hot months. The number of scabies and head pediculosis cases increased by 123 and 85 cases, respectively, in 2019. It is inferred that the effects of scabies and head pediculosis in IDPs will be considerable, with a higher carriage rate than other studies in Iraq.

A scabies outbreak in the North East Region of Ghana: The necessity for prompt intervention

Background

There is a dearth of data on scabies from Ghana. In September 2019, local health authorities in the East Mamprusi district of northern Ghana received reports of scabies from many parts of the district. Due to on-going reports of more cases, an assessment team visited the communities to assess the effect of the earlier individual treatment on the outbreak. The assessment team furthermore aimed to contribute to the data on scabies burden in Ghana and to demonstrate the use of the International Alliance for the Control of Scabies (IACS) diagnostic tool in a field survey in a resource limited setting.

Methodology/Principal findings

This was a cross sectional study. Demographic information and medical history was collected on all participants using a REDCap questionnaire. A standardised skin examination of exposed regions of the body was performed on all participants. Scabies was diagnosed based on the criteria of the International Alliance for the Control of Scabies (IACS). Participants were mostly female (61.5%) and had a median age of 18.8 years (IQR 13–25). Two hundred out of 283 (71%) of participants had scabies with most (47%) presenting with moderate disease. Impetigo was found in 22% of participants with scabies and 10.8% of those without scabies [RR 2.27 (95% CI 1.21–4.27)]. 119 participants who received scabies treatment in the past months still had clinical evidence of the disease. 97% of participants reported a recent scabies contact. Scabies was commoner in participants ≤16 years compared to those >16 years [RR 3.06 (95% CI 1.73–5.45)].

Conclusion/Significance

The prevalence of scabies was extremely high. The lack of a systematic approach to scabies treatment led to recurrence and ongoing community spread. The IACS criteria was useful in this outbreak assessment in Ghana. Alternative strategies such as Mass drug administration may be required to contain outbreaks early in such settings.

Scabies, recently categorised as a Neglected Tropical Disease by the WHO is caused by infestation with Sarcoptes scabiei and is characterised by intense pruritus and rash that typically involves the genitalia and the web spaces of the fingers and toes. It has a large global burden and is associated with significant morbidity and socio-economic burden. Secondary bacterial infections following scabies can lead to significant complications including chronic kidney disease from glomerulonephritis and possibly rheumatic heart disease. An outbreak of scabies was reported in Ghana’s East Mamprusi district in September 2019. Despite earlier treatment of individual cases, scabies prevalence was 71%. About 19% of participants had impetigo which was mostly mild in severity. Absence of a systematic approach to treat scabies led to recurrence and ongoing community spread. The recently published IACS criteria for diagnosing scabies proved useful in this outbreak assessment in Ghana. Alternative strategies such as Mass drug administration may be required to contain outbreaks in such settings.

Molecular drug targets for scabies: a medicinal chemistry perspective

Sarcoptes scabiei is a causative organism for scabies that affects an estimated global population of 300 million and remains a disease of significant concern. Recently, a number of potential drug targets were identified for scabies, including hydrolytic enzymes, inactivated paralogues of hydrolytic enzymes, inhibitors of host proteolytic enzymes and other proteins of interest. These discoveries remain confined to academic laboratories and institutions, failing to attract interest from researchers in commercial drug development. Here, we summarize the latest developments in the scabies mite biology and the drug targets that were subsequently identified, and we propose several peptide and nonpeptide ligands targeting the hot spots for protein-protein interactions. We also identify gaps in the development of ligands as inhibitors or modulators of these macromolecules.

The 2020 International Alliance for the Control of Scabies Consensus Criteria for the Diagnosis of Scabies

BACKGROUND

Scabies is a common parasitic skin condition that causes considerable morbidity globally. Clinical and epidemiological research for scabies has been limited by a lack of standardization of diagnostic methods.

OBJECTIVES

To develop consensus criteria for the diagnosis of common scabies that could be implemented in a variety of settings.

METHODS

Consensus diagnostic criteria were developed through a Delphi study with international experts. Detailed recommendations were collected from the expert panel to define the criteria features and guide their implementation. These comments were then combined with a comprehensive review of the available literature and the opinion of an expanded group of international experts to develop detailed, evidence-based definitions and diagnostic methods.

RESULTS

The 2020 International Alliance for the Control of Scabies (IACS) Consensus Criteria for the Diagnosis of Scabies include three levels of diagnostic certainty and eight subcategories. Confirmed scabies (level A) requires direct visualization of the mite or its products. Clinical scabies (level B) and suspected scabies (level C) rely on clinical assessment of signs and symptoms. Evidence-based, consensus methods for microscopy, visualization and clinical symptoms and signs were developed, along with a media library.

CONCLUSIONS

The 2020 IACS Criteria represent a pragmatic yet robust set of diagnostic features and methods. The criteria may be implemented in a range of research, public health and clinical settings by selecting the appropriate diagnostic levels and subcategories. These criteria may provide greater consistency and standardization for scabies diagnosis. Validation studies, development of training materials and development of survey methods are now required. What is already known about this topic? The diagnosis of scabies is limited by the lack of accurate, objective tests. Microscopy of skin scrapings can confirm the diagnosis, but it is insensitive, invasive and often impractical. Diagnosis usually relies on clinical assessment, although visualization using dermoscopy is becoming increasingly common. These diagnostic methods have not been standardized, hampering the interpretation of findings from clinical research and epidemiological surveys, and the development of scabies control strategies. What does this study add? International consensus diagnostic criteria for common scabies were developed through a Delphi study with global experts. The 2020 International Alliance for the Control of Scabies (IACS) Criteria categorize diagnosis at three levels of diagnostic certainty (confirmed, clinical and suspected scabies) and eight subcategories, and can be adapted to a range of research and public health settings. Detailed definitions and figures are included to aid training and implementation. The 2020 IACS Criteria may facilitate the standardization of scabies diagnosis.

Infectious disorders of the vulva

The vulva can be affected by a variety of sexually transmitted infections as well as other common infections that are not typically related to sexual transmission. Vulvar infections may adversely affect the quality of life of the patients by causing discomfort and pain. Some of these infections, especially the ulcerative ones, may also increase the risk of transmission of other infectious diseases, including HIV. Due to the recently increasing number of sexually transmitted infections and atypical presentations of these infections in immunocompromised patients, it is important for pathologists to be familiar with histopathologic features of the infectious diseases of the vulva, so that accurate diagnoses can be rendered as promptly as possible. This review discusses the clinicopathologic presentations of the non-HPV related infections of the vulva.

Scabies: Diagnostic and Therapeutic Update

BACKGROUND

Scabies is globally ubiquitous and is a significant health issue for institutions, the economically disenfranchised, resource-poor areas, and for those with weakened immune systems. Topicals are usually effective, but are cumbersome and expensive to use in large populations and for those nonadherent to topicals. Oral ivermectin became available in Canada for the off-label treatment of scabies in the fall 2018.

OBJECTIVES

To review the diagnosis and management of scabies. Dose schedules and concomitant management measures are outlined for scabies simplex and for crusted scabies. Ivermectin use is outlined.

METHODS

Medline, colleague discussions, practice review, and experience from managing scabies in institutions.

RESULTS

Oral ivermectin is safe, easier to use, cheaper, more effective, and more economical than topicals in widespread institutional scabies, for those nonadherent to topicals, and in crusted scabies.

CONCLUSIONS

Oral ivermectin is the treatment of choice in large populations, the nonadherent, and for crusted scabies. Oral ivermectin is produced by Merck Canada as Stromectol 3 mg. The treatment dose for noncrusted scabies is 200 µg/kg, taken in a single dose with food. For example, 15 mg (5 tablets) for a 70 kg person. Retreat in 10-14 days to enhance effectiveness, and perhaps to reduce scabicide resistance.

Susceptibility of patients receiving chemotherapy for haematological malignancies to scabies

BACKGROUND

Scabies is a contagious dermatosis. The risk factors for its transmission remain unclear. A scabies outbreak, involving patients who were receiving chemotherapy for haematological malignancies, occurred at our hospital.

METHODS

The outbreak population was analysed to determine whether the incidence of scabies was higher among contact patients receiving chemotherapy for haematological malignancies.

RESULTS

A patient with crusted scabies was the index case, and 18 of 78 contact healthcare workers (HCWs) and 22 of 135 contact patients were diagnosed with classical scabies. Ten of 17 contact patients with haematological malignancies and 12 of 118 contact patients with other diseases were infected with scabies. The incidence rate was significantly higher among the patients with haematological malignancies (P<0.001). The patients with haematological malignancies had a significantly lower mean minimum neutrophil count than those with other diseases (1159/μL vs 3761/μL, P=0.0012). Most haematological patients did not require special nursing assistance, suggesting that the higher incidence of scabies among these patients resulted from their immunodeficiency rather than greater skin-to-skin contact with infected HCWs.

CONCLUSION

Our study suggests that patients receiving chemotherapy for haematological malignancies are more susceptible to scabies than patients with other diseases, and require stricter protection.

Scabies and Pediculosis in Penitentiary Institutions in Poland-A Study of Ectoparasitoses in Confinement Conditions

BACKGROUND

Scabies (caused by Sarcoptes scabiei var. hominis) and pediculosis (caused by Pediculus humanus) are infectious diseases common in educational institutions and long-term care centres. The aim of the study was to assess the scale of the phenomenon in confinement conditions favouring the spread of these parasitoses.

METHODS

Data on the prevalence of scabies (2001-2015) and pediculosis (2008-2015) in Polish prisoners were provided by the Central Board of Prison Service. The information for the period between 2010 and 2015 in the Lublin Province was obtained from the District Inspectorate of the Prison Service in Lublin. Correlations between the prevalence of scabies and pediculosis and the number of prisoners were analysed, as well as correlations between the number of passes granted to prisoners and the prevalence of scabies and pediculosis in incarcerated individuals.

RESULTS

The prevalence of scabies and pediculosis in Polish prisoners has been estimated at 2.3% and 1.9%, respectively.

CONCLUSIONS

Pediculosis and scabies are still current issues in Polish prisons. Convicts returning from passes and new prisoners should be carefully examined and monitored for the presence of S. scabiei var. hominis and P. humanus invasion. Education of prisoners could be a promising tool in prevention of scabies and pediculosis in correctional settings.

A comparative study of topical tacrolimus and topical triamcinolone acetonide in nodular scabies

The aim of this study was to compare the efficacy and safety of 0.1% triamcinolone acetonide and 0.03% tacrolimus ointment for the treatment of nodular lesions of scabies. In this double-blind randomized controlled trial, 50 Indian men with postscabeitic persistent nodular lesions (labelled to have nodular scabies (NS)/postscabies prurigo (PSP)) over the external genitalia, were enrolled. They were randomized into two groups to receive either a mid-potency topical corticosteroid (TCS); triamcinolone acetonide 0.1% ointment twice daily, or topical calcineurin inhibitor (CNI); tacrolimus ointment 0.03% twice daily over the nodular lesions for 2 weeks. All patients were followed up on three visits: 1, 2, and 6 weeks, for assessment. Efficacy was evaluated by 5-point range investigator-assessed VAS, and a 4-point severity of pruritus scale (SPS) score. The mean VAS score was higher in triamcinolone group compared to tacrolimus group at both follow-ups, although statistically significant only at 2nd week visit. The fall in mean SPS at both follow-ups was also higher in the steroid group, but the difference was not statistically significant. While, the overall tolerance to either ointment was excellent, mild hypopigmentation, and epidermal atrophy were detected on dermoscopic evaluation of the treated areas at the 2nd week visit in a small subset of patients in the triamcinolone group. The frequency of relapse of lesions and/or pruritus after four weeks of the 2-week therapy was high in both the groups (higher in tarolimus group). Conclusively, although both treatment options provided safe and satisfactory short term improvement, the results from this study suggest an overall higher efficacy of a mid-potency TCS like triamcinolone 0.1% over topical CNI like tacrolimus 0.03%, in the short-term treatment of nodular lesions of NS/PSP. Topical CNIs may be considered for maintenance of effect, if prolonged therapy is warranted.

A nosocomial scabies outbreak originating from immunocompromised transplant patients in Turkey: Upholstery as a possible cause

BACKGROUND

Inpatients with crusted scabies represent an important source of nosocomial transmission with consequent outbreaks among patients and healthcare workers. This study aimed to report the course of an institutional scabies outbreak, which progressed with infestation of immunosuppressed transplant patients, health care workers, and caregivers.

METHODS

Patients diagnosed with scabies in a nosocomial outbreak in a 200-bed, tertiary hospital were included. Following a diagnosis of scabies in the index patient, strict contact isolation measures were implemented. During the outbreak, a root cause analysis (RCA) was carried out by an infection prevention and control team.

RESULTS

Forty-two individuals were affected (7 patients, 25 health care workers, and 10 family members of the patients) during the outbreak consisting of three attacks. Index case was a multiple myeloma patient who received hematopoietic stem cell transplantation and presented with crusted scabies. A RCA suggested that upholstery could serve as a means of reservoir. All upholstery of the sofa and armchairs in patient rooms as well as in lounge areas were replaced by wipeable leather material. After the 19-week course of the outbreak, no additional cases of scabies have been observed until now.

CONCLUSION

A high index of suspicion should be maintained, particularly in immunocompromised patients, in order to achieve rapid diagnosis of scabies and to implement institutional infection control measures. It should also be borne in mind that the transmission may occur through direct contact as well as fomites, such as upholstery.

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

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 (p < 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.

Molecular investigation and genetic diversity of Pediculus and Pthirus lice in France

BACKGROUND

Humans are parasitized by three types of lice: body, head and pubic lice. As their common names imply, each type colonizes a specific region of the body. The body louse is the only recognized disease vector. However, an increasing awareness of head lice as a vector has emerged recently whereas the status of pubic lice as a vector is not known since it has received little attention.

METHODS

Here, we assessed the occurrence of bacterial pathogens in 107 body lice, 33 head lice and 63 pubic lice from Marseille and Bobigny (France) using molecular methods.

RESULTS

Results show that all body lice samples belonged to the cytb Clade A whereas head lice samples belonged to Clades A and B. DNA of Bartonella quintana was detected in 7.5% of body lice samples and, for the first time to our knowledge, in 3.1% of pubic lice samples. Coxiella burnetii, which is not usually associated with transmission by louse, was detected in 3.7% of body lice samples and 3% of head lice samples. To the best of our knowledge, this is the first report of C. burnetii in Pediculus lice infesting humans in France. Acinetobacter DNA was detected in 21.5% of body lice samples, 6% of head lice samples and 9.5% of pubic lice samples. Five species were identified with A. baumannii being the most prevalent.

CONCLUSIONS

Our study is the first to report the presence of B. quintana in pubic lice. This is also the first report of the presence of DNA of C. burnetii in body lice and head lice in France. Further efforts on the vectorial role of human lice are needed, most importantly the role of pubic lice as a disease vector should be further investigated.

Where Are We With Human Lice? A Review of the Current State of Knowledge

Pediculus humanus is an obligate bloodsucking ectoparasite of human that includes two ecotypes, head louse and body louse, which differ slightly in morphology and biology, but have distinct ecologies. Phylogenetically, they are classified on six mitochondrial clades (A, B, C, D, E, and F), head louse encompasses the full genetic diversity of clades, while body louse belongs to clades A and D. Recent studies suggested that not only body louse, but also head louse can transmit disease, which warrants greater attention as a serious public health problem. The recent sequencing of body louse genome confirmed that P. humanus has the smallest genome of any hemimetabolous insect reported to date, and also revealed numerous interesting characteristics in the nuclear and mitochondrial genomes. The transcriptome analyses showed that body and head lice were almost genetically identical. Indeed, the phenotypic flexibility associated with the emergence of body lice, is probably a result of regulatory changes, perhaps epigenetic in origin, triggered by environmental signals. Current lice control strategies have proven unsuccessful. For instance, ivermectin represents a relatively new and very promising pediculicide. However, ivermectin resistance in the field has begun to be reported. Therefore, novel opportunities for pest control strategies are needed. Our objective here is to review the current state of knowledge on the biology, epidemiology, phylogeny, disease-vector and control of this fascinating and very intimate human parasite.

Update on parasitic dermatoses

These are cutaneous diseases caused by insects, worms, protozoa, or coelenterates which may or may not have a parasitic life. In this review the main ethological agents, clinical aspects, laboratory exams, and treatments of these dermatological diseases will be studied.