Estimating the global burden of scabies: what else do we need?

Scabies is one of the most common disorders identified in any estimate of global skin disease prevalence. Furthermore, quantifying its impact on individuals and societies has been problematic. There has been a lack of clear case definitions and laboratory tests. There have been few epidemiological studies, particularly those focusing on low-income countries, variation in prevalence within high-income countries, or estimates of the effect of scabies on health beyond the skin, such as renal disease or mental wellbeing. Economic studies are also lacking. However, the new strategy of integrating surveillance for skin Neglected Tropical Diseases may well produce advancements on these issues, in addition to providing an overarching structure for health improvement and disease control.

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.

Position Statement on Atopic Dermatitis in Sub-Saharan Africa: current status and roadmap.

BACKGROUND: The first International Society of Atopic Dermatitis (ISAD) global meeting dedicated to atopic dermatitis (AD) in Sub-Saharan Africa (SSA) was held in Geneva, Switzerland in April 2019. A total of 30 participants were present at the meeting, including those from 17 SSA countries, representatives of the World Health Organization (WHO), the International Foundation for Dermatology (IFD) (a committee of the International League of Dermatological Societies, ILDS www.ilds.org), the Fondation pour la Dermatite Atopique, as well as specialists in telemedicine, artificial intelligence and therapeutic patient education (TPE). RESULTS: AD is one of the most prevalent chronic inflammatory skin diseases in SSA. Besides neglected tropical diseases (NTDs) with a dermatological presentation, AD requires closer attention from the WHO and national Departments of Health. CONCLUSIONS: A roadmap has been defined with top priorities such as access to essential medicines and devices for AD care, in particular emollients, better education of primary healthcare workers for adequate triage (e.g. better educational materials for skin diseases in pigmented skin generally and AD in particular, especially targeted to Africa), involvement of traditional healers and to a certain extent also patient education, bearing in mind the barriers to effective healthcare faced in SSA countries such as travel distances to health facilities, limited resources and the lack of dermatological expertise. In addition, several initiatives concerning AD research in SSA were discussed and should be implemented in close collaboration with the WHO and assessed at follow-up meetings, in particular, at the next ISAD meeting in Seoul, South Korea and African Society of Dermatology and Venereology (ASDV) meeting in Nairobi, Kenya, both in 2020.

Systematic review of the diagnosis of scabies in therapeutic trials.

Human scabies (infestation with the mite Sarcoptes scabiei var hominis) causes a significant disease burden worldwide, yet there are no agreed diagnostic guidelines. We aimed to determine whether a consistent approach to diagnosing scabies has been used for published scabies therapeutic trials. The data sources used were the MEDLINE, Embase and Cochrane databases, from 1946 to 29 August 2013. Eligible studies were trials of therapeutic interventions against scabies in human subjects, published in English, enrolling patients with scabies, and using various therapeutic interventions. Language was a limitation of this study as some relevant trials published in languages other than English may have been excluded. Each study was reviewed by two independent authors, who assessed the clinical examination and testing approaches used for scabies diagnosis in the included studies. We found that of 71 included trials, 40 (56%) specified which clinical findings were used for diagnosis, which were predominantly rash, rash distribution, pruritus and mite burrows. Parasitological testing was used in 63% of trials (n = 45) and was used more frequently in clinic-based than in field studies. Nearly one-quarter of trials (24%, n = 17) did not define the diagnostic method used. Overall, the diagnostic approaches were poorly described, prohibiting accurate comparison of existing studies. This review further supports the need for consensus diagnostic guidelines for scabies.

Global burden of skin disease in the elderly: a grand challenge to skin health.

Skin diseases, as estimated in the global burden of disease study 2010, are a significant health problem in all global regions and many of those analyzed in this study show an increasing burden over recent years, extending into old age. Some of the conditions which have the highest impact on the elderly include non-melanoma skin cancer and skin ulceration, but bacterial skin infection, fungal disease or pruritus are all significant problems. With predicted changes in demography and a higher proportion of individuals above the age of 80 in the coming years concentrating new resources on gathering better data and devising preventative, therapeutic and palliative strategies is a priority.