Bullous Scabies

Scabies: Immunopathogenesis and pathological changes

Scabies is an itchy skin disease caused by the burrowing mite Sarcoptes scabiei. During their lifespan, the female mites invade the stratum corneum and create tunnels, in which they reside, move, feed, deposit fecal pellets, and lay eggs. Recently, scabies was included in the World Health Organization roadmap for neglected tropical diseases 2021-2030. This review attempts to summarize our knowledge about the mite's biology and the disease pathogenesis, pathological changes, and complications. Generally, the host-parasite interaction in scabies is highly complex and involves different mechanisms, some of which are yet largely unknown. Elucidation of the nature of such interaction as well as the underlying mechanisms could allow a better understanding of the mite's biology and the development of novel diagnostic and therapeutic options for scabies control programs. Moreover, identification of the molecular basis of such interaction could unveil novel targets for acaricidal agents and vaccines.

Recalcitrant nodular scabies showing excellent response to tofacitinib: five case reports

Scabies is a contagious skin condition caused by Sarcoptes scabiei, and it is always associated with an intense, unbearable, nocturnal deteriorating itch. Its presentations include classic burrows, erythema, pruritic papules, pustules, vesicles, and inflammatory nodules, with diffuse or localized distribution on the finger webs, wrist flexors, elbows, axillae, buttocks, genitalia, and breasts. Nodular scabies is an uncommon clinical variant of scabies. Its management is still challenging for some patients up to date, although topical, intralesional or systemic corticosteroids, topical calcineurin inhibitors, and crotamiton as well as cryotherapy alone or in different combinations are used. We here report five male patients of nodular scabies, aged between 14 and 25 years, who had classical scabies that had been cured by sulfur ointment for at least 4 weeks except for their itching nodules, and their residual pruritic nodules also failed in previous treatments including antihistamines, topical applying and intralesional injection of steroids as well as topical tacrolimus in different combinations before being recruited to this study. The patients were administered tofacitinib 5 mg, twice a day, which led to excellent and rapid improvement for both lesions and symptoms after 1-4 weeks of treatment, respectively, without any associations. During 6 months of follow-up, only one had re-infection of scabies associated with nodules that were cured by sulfur ointment and tofacitinib again. No adverse reaction was observed. The present results suggested that tofacitinib might be a potential agent for nodular scabies with excellent response.

The current available diagnostic tools and treatments of scabies and scabies variants: An updated narrative review

Scabies is a neglected tropical disease that continues to have global impacts and long-term health consequences. It is caused by the mite Sarcoptes scabei var. hominis, which is an obligate ectoparasite that lives in the epidermis of the human skin. Scabies is common in poor communities due to overcrowding in places like old age homes, prisons, and homeless and displaced children. However, developed countries are also susceptible to scabies infestations, such as in institutional outbreaks or small epidemics under war conditions or during natural disasters. The diagnosis of scabies may be assisted by invasive and noninvasive tools; However, the history and examination findings are usually adequate to confirm the clinical suspicion. Here, we present an updated review of scabies by focusing on the diagnostic approaches, treatment, and prevention of scabies.

Imiquimod-induced bullous pemphigoid: A case report

A 72-year-old man treated with 3.5% imiquimod cream for scalp actinic keratoses developed the usual crusted and erosive reaction but developed bullae on the scalp, as well as the limbs and torso after several weeks into treatment. Biopsy confirmed bullous pemphigoid. He was treated with clobetasol ointment, prednisone and methotrexate, with eventual disease control. He had a severe disease course. Bullous pemphigoid is usually idiopathic, but can be induced by skin trauma, as well as by several medications; this is the first report of imiquimod as a trigger. Imiquimod is a toll-like receptor 7 agonist that induces cellular apoptosis and recruits pro-inflammatory cytokines including tumour necrosis factor-alpha and interferon-alpha, which have been implicated in autoimmunity. This case highlights an unusual but severe adverse effect from topical imiquimod.

Breaking the Bubble: Bullous scabies - A case report

The article describes a rare case of bullous scabies in a 30-year-old female. Scabies is a skin condition caused by the mite Sarcoptes scabiei and is typically transmitted through skin-to-skin contact. Bullous scabies is a rare presentation of scabies and is characterized by tense bullae and blisters that resemble bullous pemphigoid. The patient presented with pruritus, bullae on the hands and feet, and papules on various body parts. After a provisional diagnosis of scabies was made, microscopic examination confirmed the presence of mites and eggs. The patient was treated with Permethrin cream and antihistamines, and her symptoms regressed over the next two months. The husband and two other family members also reported improvement after treatment. While bullous scabies is an uncommon presentation of scabies, it is important to consider it in the differential diagnosis for patients presenting with bullae and pruritus. The exact pathophysiology of bullous scabies is yet to be determined, but theories include a staph aureus superinfection or production of autoantibodies in response to scabies lytic enzymes. Early recognition and appropriate treatment can lead to good outcomes in patients with bullous scabies.

Scabies: An Itchy Twitch

One of the most common and contagious infectious dermatological pathology is scabies. It is caused by tiny mites and spreads via skin-to-skin contact. It is most prevalent in children, the elderly, and the immunocompromised. Once diagnosed, the individual and all household contacts must be treated. Scabies has conventionally been considered a disease of the developing world and is prevalent in patients from a low socioeconomic status. Herein, we present an interesting case from a tertiary care hospital in North America.

Transcriptome Analysis of Host Inflammatory Responses to the Ectoparasitic Mite Sarcoptes scabiei var. hominis

Scabies, a human skin infestation caused by the ectoparasitic mite Sarcoptes scabiei var. hominis, affects more than 200 million people globally. The prevailing knowledge of the disease process and host immune response mechanisms is limited. A better understanding of the host-parasite relationship is essential for the identification of novel vaccine and drug targets. Here we aimed to interrogate the transcriptomic profiles of mite-infested human skin biopsies with clinical manifestations of ordinary scabies subjects ("OS"; n = 05) and subjects naive to scabies ("control"; n = 03) using RNASeq data analysis. A combined clustering, network, and pathway mapping approach enabled us to identify key signaling events in the host immune and pro-inflammatory responses to S. scabiei infestation. The clustering patterns showed various differentially expressed genes including inflammatory responses and innate immunity genes (DEFB4A, IL-19, CXCL8, CSF3, SERPINB4, S100A7A, HRNR) and notably upregulation of the JAK-STAT pathway in scabies-infested samples. Mite-infested human skin biopsies (GSE178563) were compared with an ex-vivo porcine infested model (E-MTAB-6433) and human skin equivalents (GSE48459). Marked enrichment of immune response pathways (JAK-STAT signaling, IL-4 and IL-13 pathway, and Toll receptor cascade), chemokine ligands and receptors (CCL17, CCL18, CCL3L1, CCL3L3, CCR7), and cytokines (IL-13 and IL-20) were observed. Additionally, genes known for their role in psoriasis and atopic dermatitis were upregulated, e.g., IL-19. The detailed transcriptomic profile has provided an insight into molecular functions, biological processes, and immunological responses and increased our understanding about transcriptomic regulation of scabies in human.

Sarcoptes Infestation. What Is Already Known, and What Is New about Scabies at the Beginning of the Third Decade of the 21st Century?

Currently, there are three known subtypes of scabies: ordinary, crusted, and bullous. The worldwide prevalence of scabies remains high in the 21st century. To decrease the social, economic, and psychological impact on the enormous population infected, a lot of important work has been completed over the last 20 years concerning the management of scabies. For example, a standardization of guidelines for the treatment of scabies has been completed and programs have been designed for the prevention and treatment in endemic populations, called mass drug administrations. Unfortunately, these only apply to the ordinary form of scabies. Moreover, resistance to the drugs currently used in treatment is growing, which imposes the need to search for new treatments. For this purpose, new acaricides are being developed to enhance the therapeutic options for the patients' benefit and effectively treat this disease. There is also the necessity for prevention before the development of scabies. An effective vaccine has the potential to protect people before this disease, especially in endemic areas. Unfortunately, there are no such vaccines against Sarcoptes yet.

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.

Scabies: A comprehensive review and current perspectives

Human scabies is a contagious skin infestation caused by the parasitic mite Sarcoptes scabiei var. hominis. It is a common skin disease worldwide that occurs not only in the underprivileged sections of society but also in developed countries. In 2009, World Health Organization (WHO) recognized scabies as "neglected tropical disease (NTD)" or NTD thus emphasizing the need for community awareness and proper treatment strategies. This review attempts to summarize the varied clinical presentation of the disease and describes the advances in diagnosis and management including the ongoing search for novel agents to overcome the problems associated with conventional treatments. The literature research includes peer-reviewed articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) till February 2020 and reference lists of respective articles. Only articles published in English language were included.

Dipeptidyl peptidase-4 inhibitor-associated bullous pemphigoid, likely triggered by scabies, in a hemodialysis patient with human leukocyte antigen-DQB1*03:01

Bullous pemphigoid (BP) is the most common autoimmune subepidermal bullous diseases. Autoantibodies against hemidesmosomal adhesion proteins might be involved in the developing process. BP usually affects the elderly with high mortality whereas the drug-induced BP is often improved and rarely relapses after the withdrawal of the suspected drug. An accumulated evidence suggests that dipeptidyl peptidase-4 inhibitor (DPP-4I), which has been widely used as the antidiabetic drug improves glycemic control with little risk for hypoglycemia, could be an inducer of DPP-4I-associated BP (DPP-4I-BP). While the precise mechanism remains unclear, a unique immunological profile with human leukocyte antigen (HLA)-DQB1*03:01 could be a biomarker of genetic susceptibility to DPP-4I-BP. Here, we encountered an interesting case of DPP-4I-BP with HLA-DQB1*03:01, which was likely triggered by scabies. A 56-year-old Japanese male with type 2 diabetes on hemodialysis was referred to our hospital due to worsened blisters. Prior to his admission, he had been on linagliptin, a DPP-4I, for 5 months. He then suffered from scabies 2 weeks before his admission while the treatment with ivermectin failed to improve his symptom. Based on his clinical symptom, positive for anti-BP180 autoantibody in serum, and the pathological alterations of skin biopsy specimens, he was diagnosed with DPP-4I-BP. Importantly, he also carried an HLA-DQB1*03:01 allele. Oral prednisolone was subsequently administered after the discontinuation of linagliptin, and his symptom gradually disappeared. Given the fact that the DPP-4I-BP could be a life-threating disease, we should be cautious of prescribing DPP-4I in hemodialysis patients, whose immune system could be impaired.

Scabies: A Neglected Global Disease

BACKGROUND

Scabies is a skin disease caused by an obligate human parasite mite Sarcoptes scabiei var. hominis. Children under the age of two and elderly individuals are at the greatest risk. Knowledge of this condition is important for an early diagnosis to be made and treatment to be initiated.

OBJECTIVE

The review aimed to familiarize physicians with the clinical manifestations, diagnosis, evaluation, and management of scabies.

METHODS

A search was conducted using Pubmed with the built-in "Clinical Queries" tool. The search term "Scabies" was used. The categories of "epidemiology", "diagnosis", "therapy", "prevention" and "prognosis" had a limited scope for primary clinical studies. Meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews were included. Only papers published in the English language were included. A descriptive, narrative synthesis was provided of the retrieved articles.

RESULTS

Worldwide, scabies affects 200 to 300 million individuals annually. The average prevalence is estimated to be 5 to 10% in children of developing countries. Transmission usually occurs after close prolonged skin-to-skin contact. Classic scabies is characterized by an erythematous papular eruption, serpiginous burrows, and intense pruritus. Sites of predilection include the webs of the fingers, volar wrists, lateral aspects of fingers, extensor surfaces of elbows and knees, waist, navel, abdomen, buttocks, groins, and, genitals. A clinical diagnosis of classic scabies can be made on the basis of the history and clinical findings. Other clinical variants include crusted scabies, nodular scabies, and bullous scabies. Finding the mite, ova, or fecal pellets on microscopic examination of scrapings taken from skin lesions confirms the diagnosis of scabies infestation. For eradication of scabies mites, the drugs of choice are topical permethrin and oral ivermectin.

CONCLUSION

Scabies is a highly contagious parasitic cutaneous disease that is stigmatising and debilitating. Increased awareness, accurate diagnosis, and prompt treatment are essential for the effective control of scabies and for the prevention of the spread of the disease.

Genital scabies: Haven of an unwelcome guest

The itch mite Sarcoptes scabiei var. hominis has been a menace to humanity for ages. Diagnosing scabies can be a challenge in view of the varied presentations of the disease. The male genitalia are an important area of predilection of the mite. Examination of this often overlooked area is essential as it may reveal both characteristic and atypical manifestations of scabies. Genital involvement also attains special relevance in view of the possible sexual transmission of the mite. In addition to the morbidity caused by itching, patients may have to deal with myths, stigma, and embarrassment.

Hemorrhagic bulla: a rare presentation of scabies

Scabies is a contagious skin disorder with multiple presentations, it can also cause nosocomial infection sometimes. Bullous scabies is its rare subtype with male predilection, and typically occurs in the elderly with a median age of 70 years. We herein report a 90-year-old man who was hospitalized in the ward presenting with generalized infection of scabies associated with hemorrhagic bullae on both feet and hands, and leading to a prevalence in the ward. All the lesions including the bullae had excellent response to 10% sulfur ointment alone. No relapse occurred in more than 9 months of follow-up.

Case Report: Bullous Scabies in Two Children below 10 Years

Bullous scabies is an infrequent and atypical presentation of scabies, with predilection for elderly and males. Its median age of presentation is 70 years. We report two male cases of bullous scabies who were 7 years and 6 months old. Both patients had excellent response to sulfur 10% ointment alone and have had no recurrence in more than 3 months of follow-up.

Scabies masquerading as bullous pemphigoid: scabies surrepticius

Scabies, a parasitic infestation caused by the mite Sarcoptes scabiei, is diagnosed by observing either the mite, its ova, or its excrement. The mite tracts, known as burrows and a characteristic presentation of the pruritic condition, are typically found on the web spaces between the fingers. Other cutaneous lesions include excoriated papules, pustules, and vesicles. However, atypical clinical variants of scabies, such as bullous, crusted, hidden, incognito, nodular, and scalp forms of the parasitic infestation, mimic the morphologic features of other non-parasitic dermatoses. A 76-year-old man presented with pruritic blisters and urticarial plaques that demonstrated not only pathology changes, but direct immunofluorescence also showed findings of bullous pemphigoid. His condition improved, but did not resolve, with topical corticosteroid cream for the management of the primary autoimmune blistering disorder. When other family members subsequently developed scabies, the correct diagnosis for his condition, bullous scabies, was established by demonstrating mites, ova, and scybala on a mineral oil preparation from a skin scraping of a newly appearing burrow. Bullous scabies can masquerade not only clinically, but also both pathologically and immunologically as bullous pemphigoid. Scabies serrupticius is introduced as a unifying term to designate all of the non-classic presentations of S. scabiei mite infestation.

Host immune responses to the itch mite, Sarcoptes scabiei, in humans

Scabies is a parasitic disease due to infestation of skin by the burrowing mite Sarcoptes scabiei. Scabies is a major public health problem and endemic in resource poor communities worldwide affecting over 100 million people. Associated bacterial infections cause substantial morbidity, and in severe cases can lead to renal and cardiac diseases. Mite infestation of the skin causes localised cutaneous inflammation, pruritus, skin lesions, and allergic and inflammatory responses are mounted by the host against the mite and its products. Our current understanding of the immune and inflammatory responses associated with the clinical manifestations in scabies is far outweighed by the significant global impact of the disease. This review aims to provide a better understanding of human immune responses to S. scabiei in ordinary and crusted scabies phenotypes.