Scabies: diagnosis and treatment

Effects of weather and air pollution on outpatient visits for insect-and-mite-caused dermatitis: an empirical and predictive analysis

BACKGROUND

Dermatitis caused by insects and mites, diagnosed as papular urticaria or scabies, is a common skin disease. However, there is still a lack of studies about the effects of weather and air pollution on outpatient visits for this disease. This study aims to explore the impacts of meteorological and environmental factors on daily visits of dermatitis outpatients.

METHODS

Analyses are conducted on a total of 43,101 outpatient visiting records during the years 2015-2020 from the largest dermatology specialist hospital in Guangzhou, China. Hierarchical cluster models based on Pearson correlation between risk factors are utilized to select regression variables. Linear regression models are fitted to identify the statistically significant associations between the risk factors and daily visits, taking into account the short-term effects of temperatures. Permutation importance is adopted to evaluate the predictive ability of these factors.

RESULTS

Short-term temperatures have positive associations with daily visits and exhibit strong predictive abilities. In terms of total outpatients, the one-day lagged temperature not only has a significant impact on daily visits, but also has the highest median value of permutation importance. This conclusion is robust across most subgroups except for subgroups of summer and scabies, wherein the three-day lagged temperature has a negative effect. By contrast, air pollution has insignificant associations with daily visits and exhibits weak predictive abilities. Moreover, weekdays, holidays and trends have significant impacts on daily visits, but with weak predictive abilities.

CONCLUSIONS

Our study suggests that short-term temperatures have positive associations with daily visits and exhibit strong predictive abilities. Nevertheless, air pollution has insignificant associations with daily visits and exhibits weak predictive abilities. The results of this study provide a reference for local authorities to formulate intervention measures and establish an environment-based disease early warning system.

Failure of scabies treatment: a systematic review and meta-analysis

BACKGROUND

Treatment failure is considered to be an important factor in relation to the increase in scabies incidence over the last decade. However, the regional and temporal differences, in addition to the predictors of therapy failure, are unclear.

OBJECTIVES

We aimed to conduct a systematic review of the prevalence of treatment failure in patients with scabies and investigation of associated factors.

METHODS

We searched MEDLINE, EMBASE, CINAHL, Web of Science, Scopus, Global Health and the Cochrane Central Register of Controlled Trials from inception to August 2021 for randomized and quasi-randomized trials, in addition to observational studies that enrolled children or adults diagnosed with confirmed or clinical scabies treated with permethrin, ivermectin, crotamiton, benzyl benzoate, malathion, sulfur or lindane, and measured treatment failure or factors associated with treatment failure. We performed a random effects meta-analysis for all outcomes reported by at least two studies.

RESULTS

A total of 147 studies were eligible for inclusion in the systematic review. The overall prevalence of treatment failure was 15.2% [95% confidence interval (CI) 12.9-17.6; I2 = 95.3%, moderate-certainty evidence] with regional differences between World Health Organization regions (P = 0.003) being highest in the Western Pacific region (26.9%, 95% CI 14.5-41.2). Oral ivermectin (11.8%, 95% CI 8.4-15.4), topical ivermectin (9.3%, 95% CI 5.1-14.3) and permethrin (10.8%, 95% CI 7.5-14.5) had relatively lower failure prevalence compared with the overall prevalence. Failure prevalence was lower in patients treated with two doses of oral ivermectin (7.1%, 95% CI 3.1-12.3) compared with those treated with one dose (15.2%, 95% CI 10.8-20.2; P = 0.021). Overall and permethrin treatment failure prevalence in the included studies (1983-2021) increased by 0.27% and 0.58% per year, respectively. Only three studies conducted a multivariable risk factor analysis; no studies assessed resistance.

CONCLUSIONS

A second dose of ivermectin showed lower failure prevalence than single-dose ivermectin, which should be considered in all guidelines. The increase in treatment failure over time hints at decreasing mite susceptibility for several drugs, but reasons for failure are rarely assessed. Ideally, scabicide susceptibility testing should be implemented in future studies.

National survey in Switzerland calls for improved diagnosis and treatment in children with scabies

AIM OF THE STUDY

The global prevalence of scabies is estimated to be up to 200 million cases annually, with young children particularly affected. In Europe, most cases are thought to originate in migrant populations. Scabies management is challenging in children. To identify knowledge gaps and research needs, we aimed to descriptively evaluate the management of children with scabies by different Swiss healthcare providers.

METHODS

An invitation for an anonymous online survey (36 questions) was sent to members of Swiss societies of dermatologists, general practitioners, paediatricians, paediatric dermatologists, paediatric infectious diseases specialists, and tropical medicine specialists, inviting clinicians to participate from 25th May to 8th August 2020. One reminder invitation was sent. Hospital pharmacies and the distributor of permethrin were contacted to report consumption trends of scabicides in 2018 and 2019.

RESULTS

The survey was completed by 248 clinicians: 146 (59%) paediatricians, 47 (19%) dermatologists, 28 (11%) general practitioners, 6 (2%) paediatric dermatologists, 13 (5%) paediatric infectious diseases specialists, and 8 (3%) tropical medicine specialists. Most consulted up to 10 scabies cases within a 16-month period, with similar numbers in migrant and Swiss children. Dermoscopy was used by 24% of non-dermatologists. Non-dermatologists did not consider co-treatment of close contacts in up to 59% of cases. While permethrin was the first-line treatment, treatment failures were frequently reported in children aged <5 years. Up to 67% of paediatric dermatologists regularly used oral ivermectin off-label in children weighing <15 kg. None of the paediatric dermatologists, 15% of the dermatologists, and 9% of the non-dermatologists used only one treatment cycle.Scabicide consumption increased. Treatment studies on ivermectin use in children weighing <15 kg had the highest research priority.

CONCLUSION

In Switzerland, scabies is a frequent dermatosis in migrant and Swiss children. While accessible, optimal diagnostics are underutilised, and treatment is suboptimal. Permethrin resistance appears to be an increasing problem. Dermatologists regularly use ivermectin off-label in children weighing <15 kg. Treatment studies on ivermectin use in children weighing <15 kg, user-friendly diagnostic tools, new treatment protocols, and child-friendly dosage forms are needed to improve the diagnosis and treatment of children with scabies.

[Eczema and its treatment in older adults]

Eczema encompass a wide range of dermatoses that can affect elderly patients in particular. Common differential diagnoses in elderly patients include asteatotic eczema, late-onset atopic dermatitis, allergic contact dermatitis, early phases of mycosis fungoides, eczematous and pruriginous variants of premonitory bullous pemphigoid, as well as eczematized scabies and post-scabietic eczema. Given the partly overlapping clinical presentations, accurate diagnosis plays a crucial role in the management of these conditions. Therapeutic options depend on the underlying disease and necessitate an individualized approach. This review presents relevant types of eczema in older adults together with diagnostic and therapeutic approaches. In addition to confirming the diagnosis and selecting the appropriate treatment, aspects relevant to the care of older patients should be incorporated into the tailored therapeutic approach.

Severe Scabies: A French Multi-centre Study Involving 95 Patients with Crusted and Profuse Disease and Review of the Literature

The aim of this multi-centre French retrospective study was to identify severe, i.e. crusted and profuse, scabies patients. Records were retrieved from 22 Dermatology or Infectious Diseases departments in the Ile-de-France from January 2009 to January 2015 to characterize epidemiology, demography, diagnosis, contributing factors, treatment features, and outcomes in severe scabies. A total of 95 inpatients (57 crusted and 38 profuse) were included. A higher number of cases was observed among elderly patients (>75 years), mostly living in institutions. Thirteen patients (13.6%) reported a history of previously treated scabies. Sixty-three patients (66.3%) had been seen by a previous practitioner for the current episode (up to 8 previous visits). Initial misdiagnosis (e.g. eczema, prurigo, drug-related eruptions, psoriasis) was documented in 41 patients (43.1%). Fifty-eight patients (61%) had already received 1 or more previous treatments for their current episode. Forty percent received corticosteroids or acitretin for an initial diagnosis of eczema or psoriasis. Median time from the onset of symptoms to the diagnosis of severe scabies was 3 months (range 0.3-22). Itch was present in all patients at diagnosis. Most patients (n=84, 88.4%) had comorbidities. Diagnostic and therapeutic approaches varied. Complications occurred in 11.5% of cases. To date, there is no consensus for diagnosis and treatment, and future standardization of is required for optimal management.

Dermoscopic features of children scabies

Scabies is a common skin disorder, caused by the ectoparasite Sarcoptes scabiei. The scabies mites burrow is highly diagnostic but illegible by the naked eye, because it is tiny and may completely be obscured by scratch and crust. The classic technique is opening the end of an intact mite burrow with a sharp instrument and inspecting its contents in the light microscope under loupe vision. Dermatoscope is a new method to diagnose scabies, with the advantages of non-invasive and more sensitive. This study verified the characteristic manifestations of scabies under dermoscopy. Under the closer examination of the curvilinear scaly burrow, the scabies mite itself may be seen as a dark equilateral triangular structure, which is often referred to as a "jet with contrail." Besides, this study found that the positive detection rate of microscopic characteristic manifestations under the dermoscopy ordered by the external genitals, the finger seams and the trunk, which were statistically different (P-value < 0.05). Of note, this is the first study to explore the regional distribution of the characteristic dermoscopic manifestations of scabies. We are the first to propose to focus on examining the external genitalia and finger seams with dermoscopy.

Scabicidal Potential of Coconut Seed Extract in Rabbits via Downregulating Inflammatory/Immune Cross Talk: A Comprehensive Phytochemical/GC-MS and In Silico Proof

Scabies is an invasive skin condition caused by Sarcoptes scabiei mites. The present study investigates the antiscabies potential of coconut seed extract (CSE) in rabbits. GC-MS analysis of the seed oil identified 17 known compounds, while CSE phytochemical investigation afforded 4 known ones. The topical application of seed extract improved all signs of infection, and the improvement started 3 days post application. However, in vitro application of the extract caused 99% mortality of mites 1 day post application. Histopathological examination revealed the absence of inflammatory infiltration and hyperkeratosis of the epidermis, compared with ivermectin-treated groups which revealed less improvement. The mRNA gene expression results revealed a suppression of IL-1β, IL-6, IL-10, MMP-9, VEGF, and MCP-1, and an upregulation of I-CAM-1, KGF as well as TIMP-1. The docking analysis emphasized a strong binding of gondoic acid with IL-1β, IL-6, and VEGF with high binding scores of -5.817, -5.291, and -8.362 kcal/mol, respectively, and a high binding affinity of 3″(1‴-O-β-D-glucopyranosyl)-sucrose with GST with -7.24 kcal/mol. Accordingly, and for the first time, our results highlighted the scabicidal potential of coconut seed extract, which opens the gate for an efficient, cost-effective as well as herbal-based alternative for the control of scabies in rabbits.

Facilitations in the Clinical Diagnosis of Human Scabies through the Use of Ultraviolet Light (UV-Scab Scanning): A Case-Series Study

BACKGROUND

To confirm the suspicion of scabies, dermatologists have one pathognomonic sign, "the tunnel" through which Sarcoptes scabiei digs into the epidermis. Light microscopy is considered the most reliable procedure, but it is time-consuming and operator-dependent. Recently, dermoscopy has greatly improved the chances of recognizing mite in situ, but it is still linked to the examiner's experience and to the magnification capability of the device used.

METHODS

This article, based on a case-series study, describes a novel diagnostic path, which uses an ultraviolet LED source at 365 nm and a digital camera for the evaluation of lesions that raise the suspicion of scabies.

RESULTS

The gallery emits a naked-eye-visible wavy bluish-white linear luminescence, better than that of any standard lighting. UVA light is also able to identify Sarcoptes scabiei as a white or green point-shaped area. This sign can only be appreciated by enlarging its picture to full frame on a common PC monitor.

CONCLUSIONS

Ultraviolet light (365 nm) seems to offer help in the diagnosis of scabies because it saves time compared with light microscopy and because it does not require contact with the patient's skin, as in dermoscopy. Although examiner experience remains an important factor, it is easily compensated by procedural simplicity, the cost of the devices and, especially, by the clarity of the results, even in non-specific lesions.

Tropical parasitic itch in returned travellers and immigrants from endemic areas

Itch is the most common skin symptom among tropical parasitic diseases (TPD), but there are limited data about its characteristics in these conditions. In dermatology practices and travellers' health clinics in the developed world, itch is a common complaint among travellers returning from endemic areas, as well among migrants arriving from endemic areas, where they may have been exposed to TPD. Studying aspects of pruritus among TPD may lead to improvements in prompt, accurate diagnosis and management of these conditions. This review examines the major itch-inducing TPDs, including schistosomiasis, echinococcosis, onchocerciasis, scabies, cutaneous larva migrans, larva currens, African trypanosomiasis, dracunculiasis and other causes of travel associated pruritus. We focus on the link between pruritus and other symptoms, aetiology, clinical staging and therapeutic options for these parasitic illnesses. Because some tropical parasitic diseases can present with significant pruritus, we attempt to identify aspects of the pruritus that are characteristic of-or unique to-specific conditions. These diagnostic insights may help clinicians create a rational and focused differential diagnosis and help determine optimal disease management pathways. In this sense, management involves treating the individual, seeking epidemiologically linked cases, preventing recurrences or relapses, and reducing spread of the disease.

MRSA Femoral Osteomyelitis from Superinfected Scabies Lesions: A Pediatric Case Report

Scabies is a skin infestation from the Sarcoptes scabiei. It is considered a public health issue causing concern in developing countries and is considered a “neglected tropical disease” by the World Health Organization (WHO). Scabies skin lesions may cause severe itching and can be the portal of entry for opportunistic and pathogenic bacteria, which can cause serious systemic infections. We report the case of a 3-year-old boy with recurrent scabies infections who presented to the emergency department because of a fever and refusal to walk. Blood tests showed neutrophilic leukocytosis and significantly increased C reactive protein (CRP) and procalcitonin. Upon medical examination, his right thigh was extremely painful upon palpation, knee flexion was lost and he was unable to stand, so magnetic resonance imaging (MRI) was performed. MRI showed osteomyelitis of metaphysis and distal diaphysis of the right femur with associated subperiosteal purulent collection and concomitant pyomyositis and fasciitis of the distal right thigh. Blood cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA). The patient received a long course of intravenous antibiotic therapy and his condition slowly improved. Follow-up femur X-ray showed a mixed pattern of erosion and sclerosis at the meta-diaphyseal region and periosteal reaction at the diaphyseal region. This case highlights the importance of early scabies diagnosis even in Western countries where poverty and household overcrowding are uncommon. Early diagnosis, timely initiation of proper treatment and evidence of clinical resolution are important elements to prevent recurrence of infection and serious systemic superinfections even from multi-drug resistant bacteria. Clinical consequences from unrecognized disease or inadequate eradication are preventable.

Management of common scabies and postscabetic itch in adults: Lessons learned from a single-center retrospective cohort study

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Combined topical permethrin plus oral ivermectin treats common scabies

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Patients 55 years or older may be more likely to experience post-scabetic itch

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Post-scabetic itch may persist for a median of 52.5 days (interquartile range, 28-135)

Background

Common scabies can be difficult to diagnose and treat. There are limited data on the clinical characteristics of patients who may benefit from combined topical permethrin plus oral ivermectin. Postscabetic itch is common, but there is scant data describing its prognosis and management.

Objective

This study describes the clinical characteristics and evaluates treatment outcomes of participants with common scabies treated with combined topical permethrin plus oral ivermectin and describes the prognosis and management of postscabetic itch.

Methods

We conducted a single-center retrospective cohort study of participants with common scabies treated with combined topical permethrin plus oral ivermectin therapy and topical permethrin only. Participants previously treated with permethrin and/or ivermectin were excluded. The primary outcome was clinical outcome at follow-up, categorized as cure, worsening, or no change. Secondary outcomes included time from treatment initiation to cure, duration of follow-up after cure, recurrence rate, frequency of postscabetic itch, and duration of postscabetic itch.

Results

Of 55 participants treated with combined topical permethrin plus oral ivermectin, 49 (89%) achieved cure, 5 (9%) had no change, and 1 (2%) had worsening disease. Of 48 participants treated with topical permethrin only, 46 (96%) achieved cure, 2 (4%) had no change, and 0 (0%) had worsening disease. Thirty-five participants (34%) experienced postscabetic itch for 52.5 days (interquartile range, 28–135). More participants in the older (mean: 55 years; standard deviation: 21 years; p = .002) combined treatment group experienced postscabetic itch than in the younger (mean: 42 years; standard deviation: 19 years) permethrin-only treatment group (42% vs. 25%; p = .072).

Conclusion

These findings support the use of combined topical permethrin plus oral ivermectin therapy in treating common scabies, highlight that postscabetic itch can persist for longer than previously reported, and reveal a potential relationship between older age and postscabetic itch.

Dermatology for the internist: optimal diagnosis and management of atopic dermatitis

Internists are front-line health care providers that commonly provide the first encounter to patients for dermatological conditions, especially atopic dermatitis (AD). Internists need to be comfortable with managing mild-moderate AD in their practices. Criteria and guidelines established in dermatology literature are available to help the general practitioner diagnose and treat AD. AD is a systemic disease associated with multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions. Environmental factors may play a role in the development or worsening of AD; however, there is currently no strong evidence to guide specific population- or clinic-based interventions for their avoidance. While food allergies are common in AD patients, the role of food allergens as an exacerbating factor for AD is controversial. Before starting any dietary modifications, careful evaluation should be performed by an allergist. If the patient is not well-controlled despite adequate topical therapies or is experiencing severe/worsening disease, early referral to dermatology is warranted to rule out confounding diagnoses and/or escalation to systemic therapies. Finally, it is important to recognise the racial disparities present in AD and address these when formulating treatment plans.Key messages:Confounding dermatoses, either instead of or in addition to AD, should be considered in treatment-refractory AD, and the appropriate workup may be initiated while awaiting dermatology referral.AD patients have multiple cutaneous and extra-cutaneous comorbidities that warrant screening by internists, especially mental health conditions.

Scabies: Epidemiology, Diagnosis, and Treatment

BACKGROUND

Scabies is a skin infestation whose incidence is apparently rising.

METHODS

This review is based on pertinent articles retrieved by a selective search of PubMed on diagnosis and treatment strategies.

RESULTS

Thread-like papules (burrows), new, intense pruritus, and dermatitis guide the suspected diagnosis which is confirmed by the microscopic or dermatoscopic demonstration of scabies mites. The first line therapy is topical application of permethrin, in accordance with the current recommendations for its use. Other treatment options include systemic ivermectin and topical crotamiton or benzyl benzoate. A combination of permethrin and ivermectin is used to treat otherwise intractable cases and is generally indicated for the treatment of crusted scabies. Known causes of treatment failure include improper application of the external agents, failure of repeated treatment with ivermectin, incomplete decontamination of furnishings and clothes, failure to simultaneously treat contact persons, absence of written documents explaining treatment modalities, and the patient's belonging to a risk group. Even though there has not yet been any direct proof of resistance of scabies mites to permethrin, there is a rising number of welldocumented cases of poor response to this agent. Moxidectin is a new substance now undergoing clinical testing.

CONCLUSION

Treatment of scabies according to the guidelines and the additional recommendations reported here should result in effective curing, even in cases that are thought to be intractable.

Risk factors for scabies, tungiasis, and tinea infections among schoolchildren in southern Ethiopia: A cross-sectional Bayesian multilevel model

Background

Skin problems cause significant sickness in communities with poor living conditions, but they have received less attention in national or global health studies because of their low mortality rates. In many developing regions, the prevalence of parasitic skin diseases among schoolchildren is not reported. Previous studies thus have attempted to identify risk factors for these conditions using the frequentist approach. This study aimed to assess the occurrence and risk factors of skin infections among rural schoolchildren in southern Ethiopia by combining a frequentist and a Bayesian approach.

Methodology/Principal findings

Using three-stage random sampling, we assessed 864 schoolchildren aged 7–14 years from the Wonago district in southern Ethiopia. We detected potential risk factors for scabies, tungiasis, and tinea infections and recorded their hygienic practices and socio-demographic information. The frequentist model revealed a clustering effect of 8.8% at the classroom level and an insignificant effect at the school level. The Bayesian model revealed a clustering effect of 16% at the classroom level and 5.3% at the school level. Almost three-fourths of the sample had at least one type of skin problem, and boys were at higher overall risk than girls (adjusted odds ratio [aOR] 1.55 [95% Bayesian credible interval [BCI] 1.01, 2.28). Risk factors included unclean fingernails (aOR 1.85 [95% BCI 1.08, 2.97]); not washing the body (aOR 1.90 [95% BCI 1.21, 2.85]) and hair (aOR 3.07 [95% BCI 1.98, 4.57]) with soap every week; sharing a bed (aOR 1.97 [95% BCI 1.27, 2.89]), clothes (aOR 5.65 [95% BCI 3.31, 9.21]), or combs (aOR 3.65 [95% BCI 2.28, 5.53]); and living in a poor household (aOR 1.76 [95% BCI 1.03, 2.83]). Washing legs and feet with soap daily was identified as a protective factor for each of the three skin diseases (aOR 0.23 [95% BCI 0.15, 0.33]).

Conclusions/Significance

We observed high variation in skin problems at the classroom level, indicating the presence of shared risk factors in these locations. The findings suggest the need to improve children’s personal hygiene via health education by schoolteachers and health workers.

Skin problems are common disorders in resource poor settings. Scabies and tungiasis are neglected tropical diseases causing significant sickness in communities with poor living conditions. Scabies is dermatosis caused by a burrowing mite, Sarcoptes scabiei var. hominis. Tungiasis is caused by a flea, Tunga penetrans, infesting the skin, usually on the feet or hands. Tinea infection is a fungal dermatophyte infection of the skin and the most common dermatological problem among schoolchildren in Ethiopia, especially tinea capitis. Application of a Bayesian approach to identify possible risk factors for these problems has seldom been used. We found that compared to the frequentist model, the Bayesian model better explained school- and classroom-level variations in skin problems among schoolchildren. Our findings also suggest that transmission of skin infections, especially fungal and scabies infections, frequently occurs in schools and classrooms. We identified several risk factors for these conditions, including low socioeconomic status; unclean fingernails; not washing with soap at least every week; and sharing beds, clothes, and combs. Thus, it is important to improve the personal hygiene of schoolchildren through education. Regular checkups by teachers also can improve skin health and related morbidity in rural schoolchildren in southern Ethiopia.

Improved diagnosis-medication association mining to reduce pseudo-associations

BACKGROUND AND OBJECTIVE

Association rule mining has been adopted to medical fields to discover prescribing patterns or relationships among diseases and/or medications; however, it has generated unreasonable associations among these entities. This study aims to identify the real-world profile of disease-medication (DM) associations using the modified mining algorithm and assess its performance in reducing DM pseudo-associations.

METHODS

We retrieved data from outpatient records between January 2011 and December 2015 in claims databases maintained by the Health and Welfare Data Science Center, Ministry of Health and Welfare, Taiwan. The association rule mining's lift (Q-value) was adopted to quantify DM associations, referred to as Q₁ for the original algorithm and as Q₂ for the modified algorithm. One thousand DM pairs with positive Q₁-values (Q₁⁺) and negative or no Q₂-values (Q₂^- or Q₂^∅) were selected as the validation dataset, in which two pharmacists assessed the DM associations.

RESULTS

A total of 3,120,449 unique DM pairs were identified, of which there were 333,347 Q₁⁺Q₂^- pairs and 429,931 Q₁⁺Q₂^∅ pairs. Q₁⁺Q₂^- rates were relatively high in ATC classes C (29.91%) and R (30.24%). Classes L (69.91%) and V (52.52%) demonstrated remarkably high Q₁⁺Q₂^∅ rates. For the 1000 pairs in the validation, 93.7% of the Q₁⁺Q₂^- or Q₁⁺Q₂^∅ DM pairs were assessed as pseudo-associations. However, classes M (5.3%), H (4.5%), and B (4.1%) showed the highest rates of plausible associations falsely given Q₂^- or Q₂^∅ by the modified algorithm.

CONCLUSIONS

The modified algorithm demonstrated high accuracy to identify pseudo-associations regarded as positive associations by the original algorithm and would potentially be applied to improve secondary databases to facilitate research on real-world prescribing patterns and further enhance drug safety.

Mimics of Dermatitis

Dermatitis is a common condition frequently encountered by dermatologists. The diagnosis of dermatitis can be challenging because this condition is often multifactorial, and many skin diseases that can mimic dermatitis should be considered in the differential diagnosis. It is important to recognize and be familiar with these conditions because some of them can represent signs of systemic disease or malignancies and misdiagnosis can lead to mismanagement and adverse outcomes for the patient.

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.

Eleven Danish patients diagnosed with Scabies and treated with Tenutex®

Treatment with Tenutex® should be considered in patients diagnosed with scabies if the first-line treatment with 5% permethrin fails. Treatment failure with 5% permethrin may be due to tolerance or resistance in scabies mites.

Scabies involving palms in older children and adults: a changing scenario

Scabies is a highly contagious, intensely pruritic skin infestation caused by Sarcoptes scabiei var hominis. It has high prevalence in many tropical countries where crowded people live in resource-poor settings. The rash is distributed differently in adults and children. Adults manifest lesions primarily on the interdigital web spaces of the hands, flexor aspects of the wrists, dorsal feet, axillae, elbows, waist, buttocks, and genitalia. Palms (along with soles and head) are commonly involved in infants and very young children but typically absent in older age groups. Here, we report 25 older children and adult patients with scabies including involvement of the palms. If patients are left untreated for long periods of time in hot tropical climates, scabies may produce severe infestation with involvement of palms in older children and adults. We should acknowledge palms as potential body sites whose involvement warrants early and aggressive treatment in scabies.

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.

Assessing knowledge of scabies among physicians working in primary health care setting

Background:

Outbreaks of scabies have been documented in 2018 among school children in Western and Central regions of Saudi Arabia. There have been concerns about the awareness of healthcare providers.

Objective:

The objective of the current study was to evaluate the knowledge of primary health care physicians about scabies diagnosis and management, as well as the factors influencing such knowledge.

Methods:

An observational cross-sectional study was conducted between September and October 2019. The target population was physicians working in primary care centers in Riyadh. Filling either hard or soft copies of the study questionnaire was used for data collection. The knowledge score was calculated from the answers for 16 knowledge questions.

Results:

A total of 216 physicians were included in the final analysis, mainly general practitioners (56.5%) and registrars (31.5%). The overall knowledge score was 67.5%± 13.9%. The highest level of knowledge was associated with age susceptibility (80.6%), followed by clinical presentation and diagnosis (78.1%), mode of transmission (75.8%), pathogen cause & incubation period (66.9%), and finally management (61.7%). In multivariate logistic regression models, a shorter time since last time information about scabies was reviewed was significantly associated with better knowledge (defined as score > median), with odds ratio = 5.84 (95% confidence interval = 2.43–14.01). Similarly, older age and higher qualification were significantly associated with better knowledge.

Discussion:

As expected, the knowledge about scabies among primary care physicians was generally inadequate. The current findings highlight the need for educational and training programs lead by health care authorities, targeting these physicians.

Do we know how scabies outbreaks in residential and nursing care homes for the elderly should be managed? A systematic review of interventions using a novel approach to assess evidence quality

Currently no national guidelines exist for the management of scabies outbreaks in residential or nursing care homes for the elderly in the United Kingdom. In this setting, diagnosis and treatment of scabies outbreaks is often delayed and optimal drug treatment, environmental control measures and even outcome measures are unclear. We undertook a systematic review to establish the efficacy of outbreak management interventions and determine evidence-based recommendations. Four electronic databases were searched for relevant studies, which were assessed using a quality assessment tool drawing on STROBE guidelines to describe the quality of observational data. Nineteen outbreak reports were identified, describing both drug treatment and environmental management measures. The quality of data was poor; none reported all outcome measures and only four described symptom relief measures. We were unable to make definitive evidence-based recommendations. We draw on the results to propose a framework for data collection in future observational studies of scabies outbreaks. While high-quality randomised controlled trials are needed to determine optimal drug treatment, evidence on environmental measures will need augmentation through other literature studies. The quality assessment tool designed is a useful resource for reporting of outcome measures including patient-reported measures in future outbreaks.

Increase of scabies in Germany and development of resistant mites? Evidence and consequences

Scabies has been diagnosed surprisingly frequently in Germany in recent years, and the use of acaricides has risen markedly. Present figures indicate an increase in the prevalence/incidence of scabies, but do not prove or quantify it for the following reasons: (a) scabies is not a notifiable disease in Germany; (b) the diagnosis is not always confirmed lege artis by means of light microscopy or dermatoscopy (which may lead to a comparatively high proportion of false‐positive diagnoses due to the low overall prevalence of scabies); (c) repeated treatments of the same patient and treatment of contact persons are included in the total number of prescriptions. Therefore, there are no valid data on disease occurrence, either in the current situation or from previous periods. Observations of ineffective treatment with permethrin have led to speculations that Sarcoptes mites are developing resistance to this drug. However, there is little evidence for this assumption. We discuss risk groups (children, elderly people in need of care, migrant health personnel in nursing institutions, refugees, sexually active young adults) and evaluate their possible contribution, albeit in the absence of evidence. None of the groups would be solely responsible for an increased frequency. We have compiled recommendations on how the management of scabies could be improved, and present a way of differentiating permethrin resistance from application errors and/or lack of compliance. The goal is to solve the epidemiological and parasitological questions mentioned above.

Norwegian scabies - rare case of atypical manifestation

Human scabies affects all social classes and different races around the world. It is highly contagious, but the exact figures on its prevalence are unknown. A 19-year-old male patient was admitted to the emergency room reporting fever (38°C) and multiple lesions throughout the body, except face, soles, and palms. Lesions were non-pruritic, which hampered the initial diagnostic suspicion. Skin biopsy was performed, and the final diagnosis was crusted scabies (Norwegian). It was concluded that human scabies is a significant epidemic disease, due to its different clinical manifestations, and because it is extremely contagious.

[Evaluation of practices in the management of scabies in children]

BACKGROUND

Scabies has been on the rise in France in recent years and has posed therapeutic problems, mainly due to the withdrawal of benzyl benzoate. The objective of this study was to describe prescribing practices for scabies in children.

METHODS

A national survey was conducted by means of a standardized questionnaire covering various clinical situations of scabies and the drugs used preferentially according to age, which was sent out between December 2014 and March 2015 to members of the clinical research group of the French Society of Paediatric Dermatology.

RESULTS

Of the 38 experts contacted, 20 replied. For a typical case of scabies, 55% of the experts initially prescribed oral ivermectin for children aged 6 years, 15% prescribed ivermectin in children aged 2 years, and 5% in infants aged 3 months. Ivermectin was more widely prescribed after failure of prior treatment or recurrence of scabies, on skin lesions or impetigo, if precarious, especially for profuse hyperkeratotic scabies. A total of 35% of the experts reported no prescribing restrictions with regard to patient age or weight. Discrepancies were observed concerning the mode of administration and the time between consecutive doses. Esdepallethrin remained the preferred local treatment among the experts (38% of all topical prescriptions) except in asthmatic children, while permethrin was the least-prescribed topical agent.

DISCUSSION

This study confirms the heterogeneity of our practices. Formal expert recommendations are awaited, particularly concerning the use of ivermectin in infants.

Laboratory Diagnosis of Scabies Using a Simple Saline Mount: A Clinical Microbiologist's Report

Scabies is a skin condition caused by infestation of the mite Sarcoptes scabiei. Sarcoptes scabiei var. hominis is an arthropod member belonging to the order Acarina. Scabies is present throughout the world and is prevalent in all age groups, mostly involving people frequently in contact with animals, children, women, and elderly people. Predisposing factors for scabies include individuals with immunosuppressive conditions and people residing under low socioeconomic conditions. Skin lesions that occur during mite infestation closely resemble dermatological disorders caused by microbes, including fungi, parasites, and viruses. Laboratory diagnosis of scabies greatly relies on an accurate clinical suspicion and the demonstration of mites in the skin scrapings could be used for confirmation. It should be noted that a greater understanding between a clinician or a dermatologist and a clinical microbiologist is required to successfully diagnose scabies. This report details an easily performed, cost-effective method, the simple saline mount, that a clinical microbiology laboratory should follow to successfully identify mites in skin scrapings.

Cutaneous Manifestations of Selected Parasitic Infections in Western Pacific and Southeast Asian Regions

Cutaneous manifestations of parasitic infections often result in discomfort, debilitation, and even stigmatization. Data on cutaneous manifestations of parasitic infections, however, are limited. This article provides updates on the cutaneous manifestations of parasitic infections which are known to occur in Western Pacific and Southeast Asian regions, such as scabies, pediculosis, cutaneous larva migrans, larva currens, cutaneous schistosomiasis, cutaneous enterobiasis, cutaneous cysticercosis, acute dermatolymphangioadenitis (lymphatic filariasis), and cutaneous amoebiasis. The lack of epidemiological data on these conditions suggests the need for improvements in recording and reporting of cases. Utilization of advance diagnostic modalities and capacity building of health workers are important for proper case management. Cutaneous manifestations of parasitic infections are a topic rarely studied and thus represent an opportunity for further research.

Scabies among primary schoolchildren in Egypt: sociomedical environmental study in Kafr El-Sheikh administrative area

BACKGROUND/OBJECTIVES

Scabies is a major global public health issue that might affect people from all socioeconomic levels. The primary contributing factors in contracting scabies seem to be poverty and overcrowded living conditions. Scabies often spreads among schoolchildren quite rapidly, owing to their close contact and overcrowding within the schools. However, limited information is available about its risk factors and the socioeconomic correlates among schoolchildren in Egypt. This study aimed to assess the prevalence of scabies and its risk factors among primary schoolchildren in Kafr El-Sheikh administrative area, Egypt.

METHODS

This cross-sectional descriptive study was performed on primary schoolchildren in urban and rural areas of Kafr El-Sheikh administrative area. A predesigned questionnaire was used for data collection from the randomly selected 2,104 children, and clinical dermatological examination was done for them.

RESULTS

Out of 2,104 children studied, there were 92 cases of scabies with a prevalence of 4.4%. The prevalence of scabies infestation in male students was 3.9%, while it was 4.8% in females, with no statistical significance. The results showed significant variations in the risk of scabies infestation by factors such as residence, paternal education and occupation, maternal education, sleeping with others, having animals at home, dealing with animals outside the house, type of building for living, family history of itchy rash, and sharing clothes with others.

CONCLUSION

In our community, scabies is still an important health problem affecting schoolchildren, especially in rural areas. It is characterized by a complex web of causation, particularly poor living conditions and low level of parents' education.

Clinical phenotype of scabies by age

OBJECTIVE

Scabies has a clinical presentation that seems to vary according to age. We conducted a prospective study with the goal of delineating the clinical presentation of the disease into 3 groups of age: infants, <2 years; children, 2 to 15 years; and adults, >15 years.

METHODS

This trial was a prospective, multicenter observational study in consecutive patients with a confirmed diagnosis of scabies who were seen in 13 French Departments of Dermatology and Pediatric Dermatology between April 2010 and April 2011. A standardized questionnaire was completed for each patient. To identify factors associated with patient age, comparisons between the 3 age groups were conducted by using univariate and multivariate multinomial logistic regression analyses.

RESULTS

A total of 323 individuals were included; the gender ratio (female:male) was 1.2:1. In univariate analysis, infants were more likely to have facial involvement. In multivariate logistic regression, relapse was more frequent in children (odds ratio [OR]: 2.45 [95% confidence interval (CI):1.23-4.88]) and infants (OR: 3.26 [95% CI: 1.38-7.71]). In addition, family members with itch (OR: 2.47 [95% CI: 1.04-5.89]), plantar (OR: 20.57 [95% CI: 7.22-58.60]), and scalp (OR: 16.94 [95% CI: 3.70-77.51]) involvement were also found to be independently associated with the age group <2 years.

CONCLUSIONS

There is a specific clinical presentation of scabies in infants and children. Taking into account these specificities may be helpful for the early diagnosis and the identification of cases to prevent the propagation of the disease.

Developmental toxicity of benzyl benzoate in rats after maternal exposure throughout pregnancy

The maternal and fetal toxicity of benzyl benzoate, commonly used as antiparasitic insecticide, was evaluated in pregnant rats after a daily oral dose of 25 and 100 mg/kg. Biochemical, histopathological, and morphological examinations were performed. Dams were observed for maternal body weights and food and water consumption and subjected to caesarean section on (GD) 20. Maternal and fetal liver, kidney, heart, brain, and placenta were examined histopathologically under light microscope. Maternal and fetal liver and placenta were stained immunohistochemically for vascular endothelial growth factor (VEGF). Morphometric analysis of fetal body lengths, placental measurements, and fetal skeletal stainings was performed. Statistically significant alterations in biochemical parameters and placental and skeletal measurements were determined in treatment groups. In addition to histopathological changes, considerable differences were observed in the immunolocalization of VEGF in treatment groups. These results demonstrated that benzyl benzoate and its metabolites can transport to the placenta and eventually enter the fetuses.

Case for diagnosis

Human scabies is an intensely pruritic skin infestation caused by Sarcoptes scabiei var. hominis. Crusted scabies (previously known as Norwegian scabies) is a rare form, very contagious and transmitted by direct contact with the skin. Despite being readily treatable, a delayed diagnosis often leads to widespread infestation of contacts, and therefore difficult to restrain. This case concerns a patient where dermoscopy (with scabetic burrows and a visible hand-glider structure), together with direct microscopic examination, allowed a prompt diagnosis, thereby reinforcing the increasing importance of this technique in daily practice.

The elimination of scabies: a task for our generation

Scabies prevalence remains unacceptably high in many regions throughout the world. Infestation with scabies significantly impacts quality of life and is linked to pyoderma and consequently to severe long-term sequelae such as post-streptococcal glomerulonephritis. In the past, control programs using topical treatments have met with poor compliance; however, the highly effective oral agent ivermectin may offer a new paradigm in scabies management. Problems still exist with insensitive diagnostic tests, questions concerning mite reservoirs, and restrictions on who can receive ivermectin. Despite these difficulties, the elimination of scabies in communities worst affected may soon be possible.

Comparison of safety, efficacy, and cost effectiveness of benzyl benzoate, permethrin, and ivermectin in patients of scabies

OBJECTIVE

To compare three treatment modalities in scabies for safety, efficacy, and economy in a local population of Nagpur.

MATERIALS AND METHODS

This was a prospective, randomized, comparative clinical trial conducted in 103 participants, randomly allocated to three groups. First group received benzyl benzoate (BB) 25% lotion, second group received permethrin 5% cream, whereas third group received tablet ivermectin 200 mug/kg as a single dose. The participants were recalled after one week for follow-up evaluation. If there were no signs of cure, the same intervention was repeated. The participants were followed up for two weeks for cure rate, adverse drug reaction (ADR) monitoring, and postintervention observation. The follow-up was stopped after two weeks.

STATISTICS

Fischer's exact test using Graph pad Instat v 3.05.

RESULTS

Ivermectin showed 100% cure rate after two weeks of treatment. Permethrin decreased pruritus by 76% at the end of one week and had significantly better cure rate than ivermectin. At the end of two weeks treatment, this finding was reversed, that is, cure rate in ivermectin group was 100%. For cost-effectiveness analysis, treatment regimens were formulated hypothetically for comparison from Markov population tree for decision analysis. It was found that BB and ivermectin each consecutively for two weeks were most cost effective regimens giving complete cure in four weeks, while ivermectin was the fastest regimen giving the same results in two weeks.

CONCLUSION

Benzyl benzoate as first line intervention and ivermectin in the remaining gave best cost-effective results in the study patients of scabies.

Treatment of skin and soft tissue infections in the elderly: A review

BACKGROUND

Skin and soft tissue infections (SSTIs) have become the second most common type of infection among persons residing in long-term care facilities.

OBJECTIVE

The purpose of this article was to review the latest information on SSTIs among the elderly, including age-related changes, challenges, and treatment strategies in the era of emerging bacterial resistance.

METHODS

Relevant information was identified through a search of MEDLINE (1970-April 2010), International Pharmaceutical Abstracts (1970-April 2010), and Google Scholar using the terms skin and soft tissue infection, skin and skin structure infection, cellulitis, treatment guidelines, and elderly. Additional publications were found by searching the reference lists of the identified articles. Trials published since 1970 were selected for this review if they prospectively evaluated mostly adults (≥18 years of age), included >50 patients, and reported diagnostic criteria as well as clinical outcomes in patients treated for simple or complicated SSTIs.

RESULTS

Fifty-eight of 664 identified studies were selected and included in this review. A search of the literature did not identify any prospective clinical trials that were conducted exclusively in the elderly. Information on the treatment of SSTIs in the elderly was based solely on clinical studies that were conducted in adults in general. As recommended by the Infectious Diseases Society of America (IDSA) 2008 update, SSTIs should be suspected in elderly patients who have skin lesions and present with a decline in functional status, with or without fever. Patients who present with symptoms of systemic toxicity should be hospitalized for further evaluation. Current challenges in the management of SSTIs include the rapid emergence of community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA), the emergence of macrolide-resistant streptococci within the past decade, and the lack of a reliable algorithm to differentiate potentially life-threatening SSTIs that require aggressive interventions and prompt hospitalization from those that can be managed in an outpatient setting. S aureus was the most common cause of SSTIs, being isolated in 42.8% (5015/11,723) of wounds, followed by streptococci. Common SSTIs in the elderly such as shingles, diabetic foot infections, infected pressure ulcers, and scabies, and their treatment were also discussed. Based on reviews of published trials, treatment of simple SSTIs generally consisted of administration of agents with activity against S aureus and Streptococcus species such as a penicillinase-resistant β-lactam, a first-generation cephalosporin, or clindamycin. Broadening of the antimicrobial spectrum to include gram-negative and anaerobic organisms should be implemented for complicated SSTIs such as diabetic foot infections and infected pressure ulcers. Local rates of MRSA, CA-MRSA, and macrolide-resistant streptococci should be considered when selecting empiric therapy.

CONCLUSIONS

A search of the literature did not identify any prospective clinical trials on the treatment of SSTIs in the elderly; therefore, it is recommended to follow treatment based on the current IDSA guidelines. More research and publications are needed to establish proper selection of antimicrobial agents, treatment strategies, and duration of therapy of SSTIs in the elderly population.

Control strategies for endemic childhood scabies

Human scabies is a major global public health issue, with an estimated 300 million cases per year worldwide. Prevalence rates are particularly high in many third-world regions and within various indigenous communities in developed countries. Infestation with Sarcoptes Scabiei is associated with group-A streptococcal pyoderma which in turn predisposes to rheumatic fever, acute glomerulonephritis and their respective long-term sequelae: rheumatic heart disease and chronic renal insufficiency. The documented difficulties inherent in achieving scabies control within affected communities have motivated us to develop a network-dependent Monte-Carlo model of the scabies contagion, with the dual aims of gaining insight into its dynamics, and in determining the effects of various treatment strategies. Here we show that scabies burden is adversely affected by increases in average network degree, prominent network clustering, and by a person-to-person transmissibility of greater magnitude. We demonstrate that creating a community-specific model allows for the determination of an effective treatment protocol that can satisfy any pre-defined target prevalence. We find frequent low-density treatment protocols are inherently advantageous in comparison with infrequent mass screening and treatment regimes: prevalence rates are lower when compared with protocols that administer the same number of treatments over a given time interval less frequently, and frequent low-density treatment protocols have economic, practical and public acceptance advantages that may facilitate their long-term implementation. This work demonstrates the importance of stochasticity, community structure and the heterogeneity of individuals in influencing the dynamics of the human scabies contagion, and provides a practical method for investigating the outcomes of various intervention strategies.

Scabies

Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var hominis, an obligate human parasite. There are about 300 million cases of scabies in the world each year. Common predisposing factors are overcrowding, immigration, poor hygiene, poor nutritional status, homelessness, dementia, and sexual contact. Direct skin-to-skin contact between 15 and 20 minutes is needed to transfer the mites from one person to another. The diagnosis suspected with a clinical history of itch, worse at night, affecting other family members, clinical distribution, and appearance. Definite diagnosis relies on microscopic identification of the mites, eggs, or fecal pellets with 10% potassium hydroxide, ink enhancement, tetracycline fluorescence tests, or mineral oil; other methods include: epiluminescence light microscopy and S. scabiei DNA. The most commonly used treatment modalities are permethrin and ivermectin. Persistence of symptoms for 2-6 weeks after successful treatment is common. Most recurrences are because of reinfection from untreated contacts.