Role of the NLRP1 inflammasome in skin cancer and inflammatory skin diseases.

Inflammasomes are cytoplasmic protein complexes that play a crucial role in protecting the host against pathogenic and sterile stressors by initiating inflammation. Upon activation, these complexes directly regulate the proteolytic processing and activation of proinflammatory cytokines interleukin (IL)-1ß and IL-18 to induce a potent inflammatory response, and induce a programmed form of cell death called pyroptosis to expose intracellular pathogens to the surveillance of the immune system, thus perpetuating inflammation. There are various types of inflammasome complexes, with the NLRP1 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-1) inflammasome being the first one identified and currently recognized as the predominant inflammasome sensor protein in human keratinocytes. Human NLRP1 exhibits a unique domain structure, containing both an N-terminal pyrin (PYD) domain and an effector C-terminal caspase recruitment domain (CARD). It can be activated by diverse stimuli, such as viruses, ultraviolet B radiation and ribotoxic stress responses. Specific mutations in NLRP1 or related genes have been associated with rare monogenic skin disorders, such as multiple self-healing palmoplantar carcinoma; familial keratosis lichenoides chronica; autoinflammation with arthritis and dyskeratosis; and dipeptidyl peptidase 9 deficiency. Recent research breakthroughs have also highlighted the involvement of dysfunctions in the NLRP1 pathway in a handful of seemingly unrelated dermatological conditions. These range from monogenic autoinflammatory diseases to polygenic autoimmune diseases such as vitiligo, psoriasis, atopic dermatitis and skin cancer, including squamous cell carcinoma, melanoma and Kaposi sarcoma. Additionally, emerging evidence implicates NLRP1 in systemic lupus erythematosus, pemphigus vulgaris, Addison disease, Papillon-Lefèvre syndrome and leprosy. The aim of this review is to shed light on the implications of pathological dysregulation of the NLRP1 inflammasome in skin diseases and investigate the potential rationale for targeting this pathway as a future therapeutic approach.

Effectiveness of population-wide screening and mass drug administration for leprosy control in Kiribati: the COMBINE protocol.

INTRODUCTION: Progress towards leprosy elimination is threatened by increasing incidence in 'hot-spot' areas where more effective control strategies are urgently required. In these areas, active case finding and leprosy prevention limited to known contacts is insufficient for control. Population-wide active case-finding together with universal prevention through mass drug administration (MDA) has been shown to be effective in 'hot-spot' areas, but is logistically challenging and expensive. Combining leprosy screening and MDA with other population-wide screening activities such as for tuberculosis may increase programme efficiency. There has been limited evaluation of the feasibility and effectiveness of combined screening and MDA interventions. The COMBINE study aims to bridge this knowledge gap. METHODS AND ANALYSIS: This implementation study will assess the feasibility and effectiveness of active leprosy case-finding and treatment, combined with MDA using either single-dose rifampicin or rifamycin-containing tuberculosis preventive or curative treatment, for reducing leprosy incidence in Kiribati. The leprosy programme will run over 2022-2025 in concert with population-wide tuberculosis screening-and-treatment in South Tarawa. The primary research question is to what extent the intervention reduces the annual leprosy new case detection rate (NCDR) in adults and children compared with routine screening and postexposure prophylaxis (PEP) among close contacts (baseline leprosy control activities). Comparisons will be made with (1) the preintervention NCDR separably among adults and children in South Tarawa (before-after study) and (2) the corresponding NCDRs in the rest of the country. Additionally, the postintervention prevalence of leprosy obtained from a survey of a 'hot-spot' sub-population will be compared with prevalence documented during the intervention. The intervention will be implemented in collaboration with the Kiribati National Leprosy Programme. ETHICS AND DISSEMINATION: Approval has been obtained from the Kiribati Ministry of Health and Medical Services (MHMS), the University of Otago (H22/111) and the University of Sydney (2021/127) Human Research Ethics Committees. Findings will be shared with the MHMS, local communities and internationally through publication.

Macrophage Biology in Human Granulomatous Skin Inflammation.

Cutaneous granulomatoses represent a heterogeneous group of diseases, which are defined by macrophage infiltration in the skin. Skin granuloma can be formed in the context of infectious and non-infectious conditions. Recent technological advances have deepened our understanding of the pathophysiology of granulomatous skin inflammation, and they provide novel insights into human tissue macrophage biology at the site of ongoing disease. Here, we discuss findings on macrophage immune function and metabolism derived from three prototypic cutaneous granulomatoses: granuloma annulare, sarcoidosis, and leprosy.

Current understanding of frictional dermatoses: A review.

Human skin is continually exposed to internal and external forces, dynamic as well as static. The skin is normally flexible and can resist mechanical trauma due to friction, pressure, vibration, suction and laceration to a considerable degree. However, an excess of these forces can abnormally affect the structure and function of the skin, setting the stage for the development of a skin disorder. Repetitive trauma can cause lichenification, hyperpigmentation, erythema, scaling, fissuring, blisters, ulceration and chronic alterations. Frictional dermatoses is an under-recognised entity with no clear-cut definition and encompasses a variety of terms such as frictional dermatitis, frictional melanosis, frictional pigmentary dermatoses and certain other named entities, many of which are confusing. The authors propose to define frictional dermatoses as 'a group of disorders caused by repetitive trauma to the skin as a result of friction of varied aetiology which can have a wide range of cutaneous manifestations depending on the type of insult.' The exact prevalence of frictional dermatoses as a separate entity is unknown. Authors who conducted this review include a group of dermatologists and post graduate students from various institutions. Literature was reviewed through PubMed, Medscape, Medline, ResearchGate and Google Scholar using the terms 'frictional dermatitis,' 'friction and skin,' 'dermatoses and culture,' 'clothing dermatitis,' 'friction melanosis,' 'PPE induced dermatoses in COVID-19 era,' etc. A total of 122 articles were reviewed and 100 articles among them were shortlisted and included in the study, after removing duplications. The review was followed up with further deliberation which resulted in the formulation of a new definition and classification of frictional dermatoses taking into account the morphology, histopathological characteristics, anatomical region affected and the major predisposing factors. The rising incidence of mechanical dermatoses in the COVID-19 era was also emphasised.

The burden of skin diseases in India: Global Burden of Disease Study 2017.

Background The prevalence of skin diseases has increased over the last few decades, and they contribute to a significant burden on health-care systems across the world. Aims/Objective This report looks at the burden of skin and subcutaneous diseases in terms of years lived with disability and agestandardised years lived with disability in India using the Global Burden of Disease Study results from 2017. Methods Data were obtained from the Global Burden of Disease online interactive tool. Updated estimates of the world's health for 359 diseases and injuries and 84 risk factors from 1990 to 2017 are available in this interactive tool. Results Years lived with disability due to skin and subcutaneous diseases accounted for 4.02% of the total years lived with disability in India in 2017. There was an increase of 53.7% in all age standardised years lived with disability for all the skin and subcutaneous diseases from 1990 to 2017. Among skin and subcutaneous diseases, dermatitis contributed maximum years lived with disability (1.40 million; 95% uncertainty interval, 0.82-2.21) in 2017, followed by urticaria (1.02 million; 95% uncertainty interval, 0.06-1.44) with percentage increases of 48.9% and 45.7% respectively. Conclusion The burden due to infectious skin diseases (e.g., scabies, fungal skin disease and bacterial skin disease) and non-infectious diseases (e.g., dermatitis, urticaria and psoriasis) has increased over the past three decades, however the age-standardised years lived with disability for leprosy, scabies, fungal infections, sexually transmitted infections and non-melanoma skin cancer (basal cell carcinoma) has decreased. The high burden of skin and subcutaneous diseases demand that they be given due importance in the national programmes and health policy of India.

Leprosy as a Diagnostic Challenge in the United States.

A 63-year-old woman from Central Florida presented to an outside clinic with a 2-year history of a progressive, asymptomatic cutaneous eruption and arthralgias. Her past medical history was significant for reported seronegative rheumatoid arthritis, for which adalimumab, methotrexate, and low-dose prednisone therapy were initiated 5 years prior. The skin eruption occurred shortly after a 4-week hospitalization during which these medications were withheld. At her initial outside evaluation, a biopsy was performed and interpreted as subacute cutaneous lupus erythematosus (SCLE). She was treated with hydroxychloroquine without improvement. A repeat biopsy was reported as consistent with interstitial granulomatous dermatitis (IGD). There was no improvement with potent topical corticosteroids.

Histopathological Study of Skin Lesions in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

INTRODUCTION: Skin diseases are much common in developing countries. The spectrum varies according to geographic distribution, gender, age, and coexisting disorder. We conducted this study to find out the prevalence of different skin lesions and to evaluate their frequency and site of distribution. METHODS: A descriptive cross-sectional study was done in the pathology department of Kathmandu Medical college from June 2019 to November 2019 after ethical clearance. The skin biopsies were processed, sectioned and stained with Haematoxylin and eosin and evaluated. A convenience sampling method was used. Data was collected and entry was done in Statistical Packages for Social Services version 20.0, point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. RESULTS: Among 133 skin biopsies examined, noninfectious vesicobullous and vesicopustular disease were found in 42 (46.6%) cases followed by microbial disease in 22 (24.5%) and noninfectious erythematous papular and squamous disease in 21 (23.4%) cases. Spongiotic dermatitis was the most common vesicobullous disease seen in 26 (28.9%) cases. Leprosy was the commonest microbial disease found in 7 (7.8%) cases. The commonest noninfectious erythematous papular and squamous disease was erythema dyschromicum perstans seen in 7 (7.8%) cases. The commonest neoplastic lesion was keratinocytic tumor seen in 12 (32.5%) cases. The commonest tumor of the skin was intradermal nevus seen in 6 (16.3%) cases. CONCLUSIONS: Spongiotic dermatitis is a predominating non-neoplastic and overall skin lesion which was similar to the other studies done. Histopathological examination is the gold standard for the proper diagnosis as histomorphological features distinguish various skin lesions.

Paciente con dermatitis y artritis durante sus embarazos / A patient with dermatitis and arthritis during her two pregnancies

Paciente femenina que presentó durante sus dos embarazos eritema nodoso, úlceras nasales y artritis. Debido a la persistencia del eritema nodoso después del segundo parto, se practicó determinación de ANA y anti-DNA ­ IF, resultando este último positivo, por lo que se plantea el diagnóstico de lupus eritematoso y es referida al Centro Nacional de Enfermedades Reumáticas, (CNER) donde se le practicó biopsia de piel que resultó compatible con lepra: borderline o dimorfa (BB-BL) en estado reaccional tipo II (eritema nodoso leproso: ENL). Se discuten algunos de aspectos de la lepra haciendo especial énfasis en síntomas que presentó la paciente y la exacerbación de los mismos durante los embarazos, posiblemente en relación con algunos cambios inmunológicos adaptativos que son generados para mantener la tolerancia materno fetal(AU)

Female young patient with erythema nodosum, nasal ulcers and arthritis during her two pregnancies. Due to the persistence of the erythema nodosum after the second delivery, ANA and anti-DNA - IF determination were done, the latter being positive, and she was diagnosed with lupus erythematosus and was referred to the National Center for Rheumatic Diseases, where skin biopsy showed to be compatible with leprosy: borderline or dimorphic (BB-BL) in type II reactional state (leprous erythema nodosum: LEN). Some aspects of leprosy are discussed with special emphasis on symptoms that the patient presented and their exacerbation during pregnancies, possibly in relation to some adaptive immunological changes that was generated to maintain maternal fetal tolerance(AU)

Leishmaniose Tegumentar Americana: uma análise histopatológica e molecular em lesões de dermatites no estado de Pernambuco, Brasil / American Cutaneous Leishmaniasis: a histopathological and molecular analysis of dermatitis lesions in the State of Pernambuco, Brazil

Objetivo: Realizar uma análise histopatológica e molecular em biópsia de pele entre as lesões de dermatites de pacientes com suspeita de Leishmaniose Tegumentar Americana (LTA) no hospital de referência do estado de Pernambuco entre o período de 2016 e 2017. Métodos: Trata-se de um estudo descritivo observacional, no qual todos os pacientes com lesões clinicamente sugestivas para LTA incluídos no estudo foram submetidos à coleta de biópsia de pele das lesões, as quais foram analisadas pela técnica histopatológica e PCR (Reação em Cadeia de Polimerase). Resultados: Foram analisadas 24 amostras de biópsia de pele de pacientes com suspeita clínica de LTA, por testes histopatológicos e confirmação pela PCR. As amostras foram caracterizadas pela busca do DNA de Leishmania braziliensis através da PCR. Das 24 amostras estudadas, em nenhuma foi encontrado DNA de L. braziliensis. Apenas em um caso foi detectada presença de amastigotas de Leishmania pela técnica histopatológica. Outros achados microscópicos observados foram: dermatite granulomatosa (33,33%), úlcera crônica (20,83%), carcinoma basocelular (16,66%), Leishmaniose, dermatite plasmocitária e inflamação granulomatosa (8,33%) e Hanseníase (4,16%). Conclusão: O diagnóstico histopatológico detectou um caso de LTA, porém, a PCR não encontrou DNA do parasito. A análise histopatológica mostrou que as lesões dermatotrópicas dos pacientes são oriundas principalmente de úlceras, tumores de pele e hanseníase.

Objective: Accomplish a histopathological and molecular analysis in skin biopsy between the dermatitis lesions of patients with suspected American Cutaneous Leishmaniasis (ATL) at the Hospital of Reference of the State of Pernambuco between the period of 2016 and 2017. Methods: This is a descriptive, observational study in which all patients with clinically suggestive lesions for ATL included in the study were submitted to skin biopsy of the lesions and analyzed by the histopathological technique and PCR (Polymerase Chain Reaction). Results: Were analyzed 24 skin biopsy samples from patients with clinical suspicion of ATL, by histopathological tests and confirmation by PCR. Samples were characterized by the search of Leishmania braziliensis DNA through PCR. Of the 24 samples studied, no DNA of L. braziliensis was found. Only in one case was detected presence of Leishmania amastigotes by histopathological technique. Other microscopic findings were granulomatous dermatitis (33.33%), chronic ulcer (20.83%), basal cell carcinoma (16.66%), Leishmaniasis, plasmacytoma dermatitis and granulomatous inflammation (8.33%) and leprosy, 16%). Conclusion: The histopathological diagnosis detected a case of ATL, however, the PCR did not find DNA of the parasite. The histopathological analysis showed that the dermatotropic lesions of the patients come mainly from ulcers, skin tumors and leprosy.

Dapsone Hypersensitivity Syndrome (DHS): A Detrimental Effect of Dapsone? A Case Report.

BACKGROUND: Dapsone is a sulfone derived drug used in the treatment of leprosy and several chronic inflammatory dermatological diseases. Dapsone Hypersensitivity Syndrome (DHS) is characterized by fever, hepatitis, generalized exfoliative dermatitis and lymphadenopathy. It is rare and potentially fatal. CASE REPORT: We present a case report of a 52 years old female with a recent history of antecedent dapsone exposure of 100 mg daily for 2 weeks. She developed fever 10 days after exposure to dapsone therapy and was treated in various primary and tertiary centers for features of sepsis. When she presented to us, clinical features of multi-organ dysfunction and intractable sepsis was evident. She was successfully managed with intravenous corticosteroids and other supportive therapy. This case of DHS is unique due to pulmonary, hepatic and colonic involvement in addition to secondary bacterial and fungal infection, which is associated with an increased risk of mortality. CONCLUSION: As dapsone is mainstay in the treatment several infections and inflammatory conditions, further research is needed to characterize markers to diagnose DHS and to develop screening policies prior to initiation of dapsone therapy.

Granuloma multiforme: an uncommon differential for leprosy.

Granuloma multiforme (GM) is a chronic granulomatous skin condition which is clinically characterised by annular lesions mainly over sun-exposed areas and histologically by focal necrobiosis and histiocytic granulomas. Its significance lies in the fact that it can clinically resemble tuberculoid leprosy and hence it can be missed. Here, we report a case of GM from India in a 55-year-old female agriculturist, with multiple asymptomatic large annular rings of papules over the photo-distributed areas. Histopathology helps in confirming the diagnosis and in differentiating it from similar clinical and histologic mimics such as granuloma annulare, tuberculoid leprosy, interstitial granulomatous dermatitis or annular sarcoid. Though a high degree of suspicion is needed to diagnose GM, it should be considered as a differential for various annular conditions.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment.

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Cutaneous Mycobacterial Infections.

Humans encounter mycobacterial species due to their ubiquity in different environmental niches. In many individuals, pathogenic mycobacterial species may breach our first-line barrier defenses of the innate immune system and modulate the activation of phagocytes to cause disease of the respiratory tract or the skin and soft tissues, sometimes resulting in disseminated infection. Cutaneous mycobacterial infections may cause a wide range of clinical manifestations, which are divided into four main disease categories: (i) cutaneous manifestations of Mycobacterium tuberculosis infection, (ii) Buruli ulcer caused by Mycobacterium ulcerans and other related slowly growing mycobacteria, (iii) leprosy caused by Mycobacterium leprae and Mycobacterium lepromatosis, and (iv) cutaneous infections caused by rapidly growing mycobacteria. Clinically, cutaneous mycobacterial infections present with widely different clinical presentations, including cellulitis, nonhealing ulcers, subacute or chronic nodular lesions, abscesses, superficial lymphadenitis, verrucous lesions, and other types of findings. Mycobacterial infections of the skin and subcutaneous tissue are associated with important stigma, deformity, and disability. Geography-based environmental exposures influence the epidemiology of cutaneous mycobacterial infections. Cutaneous tuberculosis exhibits different clinical phenotypes acquired through different routes, including via extrinsic inoculation of the tuberculous bacilli and dissemination to the skin from other sites, or represents hypersensitivity reactions to M. tuberculosis infection. In many settings, leprosy remains an important cause of neurological impairment, deformity, limb loss, and stigma. Mycobacterium lepromatosis, a mycobacterial species related to M. leprae, is linked to diffuse lepromatous leprosy of Lucio and Latapí. Mycobacterium ulcerans produces a mycolactone toxin that leads to subcutaneous tissue destruction and immunosuppression, resulting in deep ulcerations that often produce substantial disfigurement and disability. Mycobacterium marinum, a close relative of M. ulcerans, is an important cause of cutaneous sporotrichoid nodular lymphangitic lesions. Among patients with advanced immunosuppression, Mycobacterium kansasii, the Mycobacterium avium-intracellulare complex, and Mycobacterium haemophilum may cause cutaneous or disseminated disease. Rapidly growing mycobacteria, including the Mycobacterium abscessus group, Mycobacterium chelonei, and Mycobacterium fortuitum, are increasingly recognized pathogens in cutaneous infections associated particularly with plastic surgery and cosmetic procedures. Skin biopsies of cutaneous lesions to identify acid-fast staining bacilli and cultures represent the cornerstone of diagnosis. Additionally, histopathological evaluation of skin biopsy specimens may be useful in identifying leprosy, Buruli ulcer, and cutaneous tuberculosis. Molecular assays are useful in some cases. The treatment for cutaneous mycobacterial infections depends on the specific pathogen and therefore requires a careful consideration of antimicrobial choices based on official treatment guidelines.

Dermoscopy of Pigmentary Disorders in Brown Skin.

Dermoscopy is a noninvasive technique for the diagnosis, prognosis, and monitoring of pigmentary disorders in brown skin. It can be used for the diagnosis of various facial melanoses, which can avoid the need for biopsy in many cases. It can also help in early identification of the adverse effect of topical steroids and hydroquinone when they are used for the treatment of these disorders. Dermoscopy can also reliably differentiate vitiligo from other disorders of hypopigmentation. It can also help in assessing the stability of vitiligo before surgery.