Scabies: Epidemiology, Diagnosis, and Treatment

The burden of skin diseases in China: global burden of Disease Study 2019

Skin diseases continue to affect human health and cause a significant disease burden on the healthcare system.We aimed to report the changing trends in the burden of skin disease in China from 1990 to 2019, Which has an important role in developing targeted prevention strategies. We applied Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2019 analytical tools to calculate the age-standardized Prevalence and Incidence in 2019, number of years lived with disability (YLDs) and age-standardized YLDs from 1990 to 2019 of skin and subcutaneous diseases, notifiable infectious skin diseases and skin tumors in China. Among the skin and subcutaneous diseases in China in 2019, dermatitis contributed to the greatest YLD (2.17 million, 95% uncertainty interval[UI]: 1.28-3.36). Age-standardized YLD rates for leprosy decreased from 0.09 (95%UI: 0.06-0.13) in 1990 to 0.04 (95%UI: 0.03-0.06) in 2019; the proportional decrease was 55.56% over 30 years. Age-standardized YLDs for HIV and sexually transmitted infections increased by 26% during the same time period. Age-standardized YLDs for non-melanoma skin cancer increased at a much higher rate than melanoma between 1990 and 2019. Dermatitis and scabies continue to have an important role in the burden of skin and subcutaneous disease burden in China. The burden of non-melanoma cell cancer has increased most significantly over the past three decades.

Frequent Misdiagnosis of Scabies as Eczema in China: A Descriptive Study of 23 Cases

Objective

To outline the clinical manifestations observed in patients with scabies misdiagnosed as generalized eczema, analyse the factors contributing to these misdiagnoses and explore potential reasons for the resurgence of scabies.

Patients and Methods

A retrospective analysis was performed to investigate the patients with scabies misdiagnosed as generalized eczema.

Results

We included 23 patients, with twelve (52.17%) being male and eleven (47.83%) female. The illness duration ranged from 0.5 to 7 months. Among all patients, 12 (52.17%) were residents of nursing homes, 5 (21.74%) were staff members of these facilities, 4 (17.39%) were caregivers of long-term hospitalized relatives, 1 (4.35%) was a construction worker, and 1 (4.35%) had a history of tourism. The rash predominantly affected the trunk and extremities, 12 patients (52.17%) are each involved the perineum and fingers webbings. The presentations included erythema, papules, and nodules. The main complaint of all patients was nocturnal itch. Under direct microscopy, 5 patients (21.74%) tested positive for scabies mites, and 3 (13.04%) showed histopathological features consistent with scabies. All patients were initially misdiagnosed with generalized eczema.

Conclusion

Over half of all patients diagnosed with scabies either resided or worked in long-term care facilities. The lack of awareness of scabies among medical staff in long-term care facilities readily led to frequent misdiagnosis. Comprehensive measures should be implemented urgently to strengthen disease management.

Norwegian scabies in human immunodeficiency virus and tuberculosis-infected child: A case report

Norwegian scabies is a rare scabies with the manifestation of thick crusts of the extremities of the skin that contain eggs and mites. Several conditions in which scabies infection is easily transmitted include immunocompromised, home nursing, and severe neurological disorder. The aim of this case report was to present a thorough analysis of a comprehensive resource for the management of Norwegian scabies patients, with a specific focus on individuals who also have HIV or other immunocompromising diseases. A 1-year-and-7-month-old boy was presented to the hospital with a chief complaint of a thick crust that he had experienced for four months. It began as a red papule in the lower extremity, then crusted and spread to the whole body. The patient kept scratching due to itching, had a recurrent fever and diarrhea for three months, and cough for one month. The patient was diagnosed with human immunodeficiency virus (HIV) and pulmonary tuberculosis at three months, suspected to get the infection from the parents. Sarcoptes scabiei was found from microscopy examination of skin scraping. The patient received holistic treatment, including antiretroviral drugs, antituberculosis medication, scabies treatment, and malnutrition treatment. Appropriate scabies treatment aimed at peeling crusted skin, relieving itching, and increasing the patient ability to use the extremities. Comorbidity conditions caused by HIV and pulmonary tuberculosis should also be treated to optimize the outcome. The patient was discharged in good condition with sanitation education and regular follow-up at the outpatient clinic. This case highlights that Sarcoptes scabiei infestation may be a clue to an immunocompromised condition. Holistic therapy aiming to cure underlying infection, infestation and underlying nutrition and psychosocial problems must be addressed to fully cure this high-burden case.

Risk factors for scabies in hospital: a systematic review

BACKGROUND

Annually, 175.4 million people are infected with scabies worldwide. Although parasitic infections are important nosocomial infections, they are unrecognized compared to bacterial, fungal, and viral infections. In particular, nonspecific cutaneous manifestations of scabies lead to delayed diagnosis and frequent nosocomial transmission. Hospital-based studies on the risk factors for scabies have yet to be systematically reviewed.

METHODS

The study followed the PRISMA guidelines and was prospectively registered in PROSPERO (CRD42023363278). Literature searches were conducted in three international (PubMed, Embase, and CINAHL) and four Korean (DBpia, KISS, RISS, and Science ON) databases. We included hospital-based studies with risk estimates calculated with 95% confidence intervals for risk factors for scabies infection. The quality of the studies was assessed using the Joanna Briggs Institute critical appraisal tools. Two authors independently performed the screening and assessed the quality of the studies.

RESULTS

A total of 12 studies were included. Personal characteristics were categorized into demographic, economic, residential, and behavioral factors. The identified risk factors were low economic status and unhygienic behavioral practices. Being a patient in a long-term care facility or institution was an important factor. Frequent patient contact and lack of personal protective equipment were identified as risk factors. For clinical characteristics, factors were categorized as personal health and hospital environment. People who had contact with itchy others were at higher risk of developing scabies. Patients with higher severity and those with a large number of catheters are also at increased risk for scabies infection.

CONCLUSIONS

Factors contributing to scabies in hospitals range from personal to clinical. We emphasize the importance of performing a full skin examination when patients present with scabies symptoms and are transferred from settings such as nursing homes and assisted-living facilities, to reduce the transmission of scabies. In addition, patient education to prevent scabies and infection control systems for healthcare workers, such as wearing personal protective equipment, are needed.

Ivermectin: A Multifaceted Drug With a Potential Beyond Anti-parasitic Therapy

Ivermectin was first discovered in the 1970s by Japanese microbiologist Satoshi Omura and Irish parasitologist William C. Campbell. Ivermectin has become a versatile pharmaceutical over the past 50 years. Ivermectin is a derivative of avermectin originally used to treat parasitic infections. Emerging literature has suggested that its role goes beyond this and may help treat inflammatory conditions, viral infections, and cancers. Ivermectin's anti-parasitic, anti-inflammatory, anti-viral, and anticancer effects were explored. Its traditional mechanism of action in parasitic diseases, such as scabies and malaria, rests on its ability to interfere with the glutamate-gated chloride channels in invertebrates and the lack of P-glycoprotein in many parasites. More recently, it has been discovered that the ability of ivermectin to block the nuclear factor kappa-light-chain enhancer of the activated B (NF-κB) pathway that modulates the expression and production of proinflammatory cytokines is implicated in its role as an anti-inflammatory agent to treat rosacea. Ivermectin has also been evaluated for treating infections caused by viruses, such as SARS-CoV-2 and adenoviruses, through inhibition of viral protein transportation and acting on the importin α/β1 interface. It has also been suggested that ivermectin can inhibit the proliferation of tumorigenic cells through various pathways that lead to the management of certain cancers. The review aimed to evaluate its multifaceted effects and potential clinical applications beyond its traditional use as an anthelmintic agent.

Case report of crusted scabies, brief review of its pathophysiology and latest data

Background

Crusted scabies is a rare form of parasitic infection provoked by a massive infestation of the ectoparasite Sarcoptes scabiei varietas hominis on human skin. It is an extremely contagious type of disease and can even lead to a social stigma. In European countries like Greece, many cases remain undiagnosed for long periods, causing extreme distress in the patient's everyday life and social environment.

Case Description

Herein, we present a case of an 86-year-old woman with crusted scabies in Greece, who remained undiagnosed for 5 months. Massive hyperkeratotic plaques on the extremities, and face, palmoplantar keratoderma, and numerous small erythematous papules on the torso with extreme itch were the main clinical manifestations of the patient. Dermoscopy revealed the parasite. All necessary decontamination measures were taken by personnel. Treatment was administered and a complete cure of the disease was observed.

Conclusions

In this case, the use of dermoscopy has attributed to precise crusted scabies diagnosis and acute pharmacological management of the patient. Early diagnosis of such diseases not only saves patients from lethal secondary infections, but also reduces the risk of a massive scabies outbreak. We also conducted a mini-review, analyzing all recent data concerning crusted scabies macroscopic, dermatoscopic, and histological images. All new information concerning the pathophysiological mechanism of crusted scabies manifestation, updated treatment options, and potential resistance to widely-used treatments are provided.

The hidden scabies: a rare case of atypical Norwegian scabies, case report and literature review

BACKGROUND

Norwegian scabies is a rare dermatological manifestation that usually affects the most fragile populations, such as elderly and immunocompromised patients, and its diagnosis is quite complex, due to its low prevalence in the general population and because of a broad spectrum manifestation.

CASE PRESENTATION

Here we describe a rare case of Norwegian scabies that was previously misdiagnosed in a sixteen year old patient affected by Down syndrome and we conducted a non-systematic literature review about this topic. Lesions were atypical, pruritic and associated with periodic desquamation of the palms and soles and after a series of specialist evaluations, she finally underwent topical treatment with complete remission.

CONCLUSION

It is therefore crucial to take in consideration the relation between Down syndrome and community acquired crusted scabies, to enable preventative measures, early detection, and proper treatment.

The Itchy Truth About Scabies: A Case of Asymptomatic Carrier Transmission and Treatment Failure

Scabies, a common and highly contagious skin infestation, is caused by the mite Sarcoptes scabiei var. hominis. Identifying individuals with scabies often poses a diagnostic challenge, as its clinical features resemble other dermatologic conditions such as drug reactions, atopic dermatitis, and contact dermatitis. Furthermore, the cutaneous manifestations arise from delayed-type immunologic reactions to the mites and their byproducts, allowing some individuals to carry the mite without showing symptoms. The significant transmissibility of scabies, along with the potential for asymptomatic carriers, creates multiple treatment hurdles for cohabiting individuals, as the failure to treat all close contacts can result in re-infestation. This report presents the case of a 46-year-old Vietnamese male who suffered from a worsening erythematous, scaly, and pruritic rash for four months. Despite being prescribed topical corticosteroids by three different dermatologists, his rash persisted. Upon thorough evaluation, scabies was diagnosed. The patient was treated with scabicidal agents, which initially alleviated his symptoms; however, three weeks later, his symptoms resurfaced. Further investigation revealed that his wife was an asymptomatic carrier who had not received treatment. This case highlights the clinical features, pathogenesis, and treatment options for scabies while emphasizing the importance of promptly identifying and treating all close contacts.

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.

Factors Affecting Topical Treatment Success in Pediatric Scabies Cases: A Cross-Sectional Study

INTRODUCTION

Scabies is a common disease that affects the pediatric population. Treatment failure and relapse occur frequently in children.

OBJECTIVES

We aimed to identify the factors that affect topical treatment success in pediatric scabies patients.

METHODS

A multicenter cross-sectional study was conducted from April 2022 to December 2022. Pediatric scabies cases were classified as belonging to either the treatment failure (TF) group or the treatment success (TS) group.

RESULTS

We enrolled 170 patients for the study. In the TF group, the presence of symptomatic household members and referrals from physicians other than dermatologists were more common (both P < 0.001), and relapse rates and total symptom duration were higher (P = 0.007, P < 0.001, respectively). Regarding treatment agents, 5% permethrin was more commonly used in the TF group (71.1% versus 25%; P < 0.001). The proportion of patients treated with sulfur preparations was significantly higher in the TS group (60.7% versus 16.9%; P < 0.001). Misapplication of topical therapy was significantly more common in the TF group (P < 0.001), with statistically significant errors being (i) lack of treatment of close contacts (p<0,001), (ii) single application (P < 0.001), and (iii) local application (P = 0.027). A multivariate analysis revealed that TS was mainly associated with (i) the presence of atopy (odds ratio [OR] 6.12, 95% CI: 1.39-27.04), (ii) the absence of symptomatic household members (OR 6.31, 95% CI: 2.14-18.63), and (iii) presentation to a dermatologist rather than another specialist (OR 6.51, 95% CI: 2.11-20.13). The use of permethrin negatively affected treatment success (OR 0.22, 95% CI: 0.07-0.71).

CONCLUSIONS

Pediatric scabies patients should be treated before other family members become infested and with topicals other than permethrin. In addition, awareness of scabies needs to be increased among non-dermatologists.

Dermoscopic and reflectance confocal microscopic features of children scabies

OBJECTIVE

To summarize the image features of dermatoscopy and reflectance confocal microscopy (RCM) in children with scabies, and to explore the clinical significance in the diagnosis of children scabies.

METHODS

A retrospective analysis was conducted on 102 children scabies diagnosed clinically in the dermatology outpatient department of Tianjin Children's Hospital from April 2018 to June 2022. All children were examined by dermatoscopy and RCM, and images were collected.

RESULTS

102 patients, 92 patients (90.2%) showed characteristic dermoscopic manifestations: white tunnels and small brown or dark brown triangular structures at their ends. 91 patients (89.2%) showed characteristic reflectance confocal microscopic manifestations: tunnels, scabies mites, feces, and eggs in the epidermal layer. All patients showed different degrees of non-specific manifestations of dermoscopy and RCM.

CONCLUSION

Children scabies have typical dermatoscopic and reflectance confocal microscopic characteristics, and dermatoscopy and RCM are effective non-invasive diagnostic methods with high clinical application value in the diagnosis and differential diagnosis of children scabies.

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.

Therapeutische Besonderheiten bei Erkrankungen der Mamillenhaut

Die Mamillenregion ist durch besondere anatomische Verhältnisse charakterisiert und lässt sich aus dermatologischer Perspektive in Brusthaut, Haut des Brustwarzenhofes (Areola) und Haut der Brustwarze (Papilla mammae) unterteilen. Im klinischen Zusammenhang sind die Brustwarzen häufig während der Stillzeit durch mechanische Beanspruchung, Milieuänderung mit Mazeration durch den Milchfluss sowie durch mikrobielle Erreger alteriert. Zudem besteht hier die Gefahr der Entwicklung einer Mastitis puerperalis. Außerhalb der Schwangerschaft und Stillzeit finden sich gelegentlich an der Mamillenhaut Ekzemerkrankungen, häufig bei atopischer Disposition (atopisches Mamillenekzem) oder als irritatives Kontaktekzem („joggers nipple“). Seltener werden allergische Kontaktekzeme auf Konservierungsstoffe von Topika oder Metallen (Piercings) beobachtet. Auch im Rahmen einer Skabiesinfestation wird eine Beteiligung der Mamillen, insbesondere bei Frauen, regelmäßig beobachtet. Von großer klinischer Bedeutung sind seltene, präinvasive Läsionen eines Mammakarzinoms oder der Morbus Paget der Mamille vom extramammären Typ. Durch die besonderen anatomischen Gegebenheiten ist es naheliegend, dass bei der Anwendung von Topika sich auch spezifische Penetrationsbedingungen ableiten. Experimentelle Untersuchungen an Humanhaut ex vivo legen nahe, dass in Abhängigkeit von der Molmasse und der Löslichkeit des Arzneistoffs sowie des eingesetzten Vehikelsystems eine deutliche Zunahme der kutanen Bioverfügbarkeit, insbesondere an der Brustwarze selbst durch den transpapillären Diffusionsweg, auftreten kann. Dies sollte insbesondere bei der topischen Anwendung von Arzneistoffen mit bekanntem dosisabhängigem Nebenwirkungspotenzial (z. B. Glukokortikoiden) beachtet werden. Allerdings fehlt dafür bisher eine klinische Evidenz.

Crotamiton derivative JM03 extends lifespan and improves oxidative and hypertonic stress resistance in Caenorhabditis elegans via inhibiting OSM-9

While screening our in-house 1072 marketed drugs for their ability to extend the lifespan using Caenorhabditis elegans (C. elegans) as an animal model, crotamiton (N-ethyl-o-crotonotoluidide) showed anti-aging activity and was selected for further structural optimization. After replacing the ortho-methyl of crotamiton with ortho-fluoro, crotamiton derivative JM03 was obtained and showed better activity in terms of lifespan-extension and stress resistance than crotamiton. It was further explored that JM03 extended the lifespan of C. elegans through osmotic avoidance abnormal-9 (OSM-9). Besides, JM03 improves the ability of nematode to resist oxidative stress and hypertonic stress through OSM-9, but not osm-9/capsaicin receptor related-2 (OCR-2). Then the inhibition of OSM-9 by JM03 reduces the aggregation of Q35 in C. elegans via upregulating the genes associated with proteostasis. SKN-1 signaling was also found to be activated after JM03 treatment, which might contribute to proteostasis, stress resistance and lifespan extension. In summary, this study explored a new small molecule derived from crotamiton, which has efficient anti-oxidative, anti-hypertonic, and anti-aging effects, and could further lead to promising application prospects.