Arsenical keratoses in Bangladesh--update and prevention strategies

Arsenical keratosis in China: A case report and review of the literature

BACKGROUND

Arsenical keratosis is a precancerous dermatosis which could be induced by long-term exposure to arsenic poisoning. Arsenic is often added to traditional Chinese medicine in a non-compliant manner to increase the effectiveness of psoriasis treatment, which is often the main cause of arsenic poisoning in Chinese patients with psoriasis.

OBJECTIVES

We performed a systemic review of arsenic keratosis during the past 32 years to better understand the sources, treatment, and prognosis of arsenic keratosis in China.

METHODS

We searched Medline/PubMed, Embase, CNKI, and Wanfang databases for research studies published between 1992 and 2024. A total of 64 papers with 78 individual Chinese of arsenical keratosis were included in this analysis.

RESULTS

Of the patients included in the analysis, 92.21% of arsenic poisoning was due to iatrogenic factors: Chinese traditional medicine. Seventy-six patients (98.70%) had skin manifestation of hyperkeratotic papules and plaques, 68 patients (88.31%) had hyperpigmentation, 43 cases (55.84%) had hypopigmentation, and only 4 had a clear indication of Mees' lines in nails. A total of 52.63% of patients presented with tumors, including squamous cell carcinoma, Bowen's disease, and basal cell carcinoma. For patients with tumors, 20 opted for surgery, 6 for radiotherapy, and 3 for PDT. All patients with only cutaneous tumors are currently well-controlled. Death occurred in one patient with metastatic squamous cell carcinoma. Keratinizing papules improved significantly in 70.59% of patients treated with Acitretin Capsules.

CONCLUSIONS

In this study, arsenic sources in Chinese patients were mainly from traditional Chinese medicine, and there were no reports of exposure to water sources or occupational sources in the past 32 years. Most of the patients showed keratinizing papules and pigmentation, and more than 1/2 of the patients showed skin tumors, mainly squamous cell carcinoma. The treatments of tumors are mainly surgical treatment, PDT and radiotherapy can also be selected. The improvement in keratinizing rash was greater than 70% with acitretin capsules. Patients with this disease should be regularly followed up for early detection and timely treatment of potential malignant tumors.

Prevalence of arsenic-induced skin lesions and associated factors in Ethiopia: Community-based study

The study aimed to assess the prevalence of arsenic-induced skin lesions and associated factors among the population in the Adami Tulu Jido Kombolcha district, Ethiopia. A community-based cross-sectional study design was employed among 403 participants from June 02-20, 2022. A two-stage cluster sampling method was conducted to select study subjects. A pretested structured and semi-structured interview questionnaire and observation using a WHO flow chart were used for data collection. Data analysis was performed using SPSS version 24 statistical software for Windows. A multivariable binary logistic regression model was applied to examine the relationship between predictor variables and an outcome variable. The degrees of association between outcomes and predictor variables were assessed using ORs and 95% CIs, and P-values < 0.05 were considered significant. The prevalence of arsenic-induced skin lesions (arsenicosis) in the study area was 2.2% [95% CI: 1.0-3.7]. The most common arsenic-induced manifestation was keratosis (55.6%), followed by hyperpigmentation (33.3%) and hyperkeratosis (11.1%). Consumption of well water, smoking cigarettes, and chewing khat were significantly associated with arsenic-induced skin lesions. Therefore, the findings of this study should trigger further research on arsenic exposure and health risks.

Mechanisms Associated with Cognitive and Behavioral Impairment Induced by Arsenic Exposure

Arsenic (As) is a metalloid naturally present in the environment, in food, water, soil, and air; however, its chronic exposure, even with low doses, represents a public health concern. For a long time, As was used as a pigment, pesticide, wood preservative, and for medical applications; its industrial use has recently decreased or has been discontinued due to its toxicity. Due to its versatile applications and distribution, there is a wide spectrum of human As exposure sources, mainly contaminated drinking water. The fact that As is present in drinking water implies chronic human exposure to this metalloid; it has become a worldwide health problem, since over 200 million people live where As levels exceed safe ranges. Many health problems have been associated with As chronic exposure including cancer, cardiovascular diseases, gastrointestinal disturbances, and brain dysfunctions. Because As can cross the blood-brain barrier (BBB), the brain represents a target organ where this metalloid can exert its long-term toxic effects. Many mechanisms of As neurotoxicity have been described: oxidative stress, inflammation, DNA damage, and mitochondrial dysfunction; all of them can converge, thus leading to impaired cellular functions, cell death, and in consequence, long-term detrimental effects. Here, we provide a current overview of As toxicity and integrated the global mechanisms involved in cognitive and behavioral impairment induced by As exposure show experimental strategies against its neurotoxicity.

Iatrogenic Arsenism Characterized by Palmoplantar Hyperkeratosis and Diffused Skin Cancers for Over Decades

ABSTRACT

Chronic arsenism usually occurs after a long-term unawareness of arsenic exposure from environment, occupation, food, and water. We here reported 3 cases with diffused arsenic keratosis and skin cancers derived from long-term arsenic medication ingestion. In these cases, hyperkeratotic skin lesions were initially found on palms and soles, slowly progressed to every part of the skin and lasted maximally for over 30 years. Skin cancers were diagnosed and removed intermittently within decades, but with no malignancies in other organs. Oral retinoids combing with topical 5- fluorouracil and photodynamic treatment yielded a desirable outcome.

South Asian Health: Inflammation, Infection, Exposure, and the Human Microbiome

This paper presents the results of the literature review conducted for the working group topic on inflammation, infection, exposure, and the human microbiome. Infection and chronic inflammation can elevate risk for cardiovascular disease and cancer. Environmental exposures common among South Asian (SA) subgroups, such as arsenic exposure among Bangladeshis and particulate matter air pollution among taxi drivers, also pose risks. This review explores the effects of exposure to arsenic and particulate matter, as well as other infections common among SAs, including human papillomavirus (HPV) and hepatitis B/C infection. Emerging research on the human microbiome, and the effect of microbiome changes on obesity and diabetes risk among SAs are also explored.

Deciphering the molecular events during arsenic induced transcription signal cascade activation in cellular milieu

Anthropogenic sources of arsenic poses and creates unintentional toxico-pathological concerns to humans in many parts of the world. The understanding of toxicity of this metalloid, which shares properties of both metal and non-metal is principally structured on speciation types and holy grail of toxicity prevention. Visible symptoms of arsenic toxicity include nausea, vomiting, diarrhea and abdominal pain. In this review, we focused on the dermal cell stress caused by trivalent arsenic trioxide and pentavalent arsanilic acid. Deciphering the molecular events involved during arsenic toxicity and signaling cascade interaction is key in arsenicosis prevention. FoxO1 and FoxO2 transcription factors, members of the Forkhead/Fox family, play important roles in this aspect. Like Foxo family proteins, ATM/CHK signaling junction also plays important role in DNA nuclear factor guided cellular development. This review will summarize and discuss current knowledge about the interplay of these pathways in arsenic induced dermal pathogenesis.

Evaluation of the quality of life in patients with arsenic keratosis

BACKGROUND

Chronic exposure to inorganic arsenic is an important public health problem and leads to hyperpigmentation, hyperkeratosis, Bowen's disease and non-melanoma skin cancers in humans. Arsenic keratosis is the most common skin change that is associated with arsenic exposure. It may be an indicator of arsenic induced health hazards.

OBJECTIVE

To determine the needs of patients with arsenic keratosis by evaluating the impact of disease on the quality of life with respect to treatment and provide rehabilitation services.

METHODS

A total of 47 subjects with arsenic hyperkeratosis, were enrolled in this crossover study. The demographics, smoking status and the presence of chronic diseases diagnosed by the physician were recorded. Weight and height of the subjects were measured and BMI was calculated. The patients were asked to respond the visual analogue scale and EuroQoL-5D scales for assessing the pain and quality of life impairment associated with arsenic hyperkeratosis.

RESULTS

In the study group, moderate to severe problems were reported in 78.7% of patients for pain/uncomfortable condition domains and in 91.5% in anxiety/depression domains. Lower quality of life was reported in those with associated chronic disorders, at an advanced age, in thin patients and in those with severe lesions.

CONCLUSION

According to our knowledge, our study is the first one measuring the quality of life in patients with arsenic keratosis in the literature. By this study, we tried to underline the guidance of health services to be developed towards the needs of patients and the need for the development of new health policies by determining the requirements of these patients.

A retrospective review of the dermatologic manifestations of chronic arsenic poisoning in the Philippines

BACKGROUND

The Section of Dermatology of the University of the Philippines, Philippine General Hospital, reported a case of chronic arsenic poisoning from a community in Luzon island to the Department of Health resulting in the conduct of two health and environmental assessment missions in December 2014.

OBJECTIVE

To describe the demographic profile and cutaneous manifestations of chronic arsenic poisoning among affected residents in Luzon, Philippines.

METHODS

A review of the medical records of 116 residents screened during the health assessment missions in December 2014 was conducted.

RESULTS

Among the 116 residents screened, 81 (70%) had clinically confirmed arsenic keratoses and hyperpigmentation. Among them, 52 were males and 29 were females with age range of 4-82 years. Two cases of squamous cell carcinoma in situ were detected through skin biopsy. High levels of arsenic in the tap water and topsoil supported the occurrence of an epidemic of chronic arsenic poisoning.

CONCLUSION

Specific dermatologic findings of arsenic keratoses and pigmentation were common among the residents screened. Significantly higher occurrence of arsenic keratoses was seen in adults.

Arsenic and lung disease mortality in Bangladeshi adults

BACKGROUND

Chronic arsenic exposure through drinking water is a public health problem affecting millions of people worldwide, including at least 30 million in Bangladesh. We prospectively investigated the associations of arsenic exposure and arsenical skin lesion status with lung disease mortality in Bangladeshi adults.

METHODS

Data were collected from a population-based sample of 26,043 adults, with an average of 8.5 years of follow-up (220,157 total person-years). There were 156 nonmalignant lung disease deaths and 90 lung cancer deaths ascertained through October 2013. We used Cox proportional hazards models to estimate adjusted hazard ratios and 95% confidence intervals (CIs) for lung disease mortality.

RESULTS

Creatinine-adjusted urinary total arsenic was associated with nonmalignant lung disease mortality, with persons in the highest tertile of exposure having a 75% increased risk for mortality (95% CI = 1.15-2.66) compared with those in the lowest tertile of exposure. Persons with arsenical skin lesions were at increased risk of lung cancer mortality (hazard ratio = 4.53 [95% CI = 2.82-7.29]) compared with those without skin lesions.

CONCLUSIONS

This prospective investigation of lung disease mortality, using individual-level arsenic measures and skin lesion status, confirms a deleterious effect of ingested arsenic on mortality from lung disease. Further investigations should evaluate effects on the incidence of specific lung diseases, more fully characterize dose-response, and evaluate screening and biomedical interventions to prevent premature death among arsenic-exposed populations, particularly among those who may be most susceptible to arsenic toxicity.

Novel medical strategies combating nonmelanoma skin cancer

The incidence of nonmelanoma skin cancer (NMSC) continues to rise, partly because of aging, the frequency of early childhood sunburns, and sporadic extreme recreational sun exposure. A nonsurgical approach to selected cutaneous malignancy could possibly reduce the cost as well as morbidity of surgical treatment for NMSC. There has been growing interest in isolating compounds that could suppress or reverse the biochemical changes necessary for cutaneous malignancies to progress by pharmacologic intervention. By targeting diverse pathways recognized as important in the pathogenesis of nonmelanoma skin cancers, a combination approach with multiple agents or addition of chemopreventative agents to topical sunscreens may offer the potential for novel and synergistic therapies in treating nonmelanoma skin cancer. This preliminary information will expand to include more therapeutic options for NMSC in the future.

Stable groundwater quality in deep aquifers of Southern Bangladesh: the case against sustainable abstraction

In forty six wells >150 m deep, from across the arsenic-polluted area of south-central Bangladesh, groundwater composition remained unchanged between 1998 and 2011. No evidence of deteriorating water quality was found in terms of arsenic, iron, manganese, boron, barium or salinity over this period of 13 years. These deep tubewells have achieved operating lives of more than 20 years with minimal institutional support. These findings confirm that tubewells tapping the deep aquifers in the Bengal Basin provide a safe, popular, and economic, means of arsenic mitigation and are likely to do so for decades to come. Nevertheless, concerns remain about the sustainability of a resource that could serve as a source of As-safe water to mitigate As-pollution in shallower aquifers in an area where tens of millions of people are exposed to dangerous levels of arsenic in well water. The conjunction of the stable composition in deep groundwater and the severe adverse health effects of arsenic in shallow groundwater lead us to challenge the notion that strong sustainability principles should be applied to the management of deep aquifer abstraction in Bangladesh is, the notion that the deep groundwater resource should be preserved for future generations by protecting it from adverse impacts, probably of a minor nature, that could occur after a long time and might not happen at all. Instead, we advocate an ethical approach to development of the deep aquifer, based on adaptive abstraction management, which allows possibly unsustainable exploitation now in order to alleviate crippling disease and death from arsenic today while also benefiting future generations by improving the health, education and economy of living children.

Cytotoxicity patterns of arsenic trioxide exposure on HaCaT keratinocytes

BACKGROUND

Arsenic is a ubiquitous environmental toxicant, and abnormalities of the skin are the most common outcomes of long-term, low-dose, chronic arsenic exposure. If the balance between keratinocyte proliferation, differentiation, and death is perturbed, pathologic changes of the epidermis may result, including psoriasis, atopic dermatitis, and certain forms of ichthyosis. Therefore, research investigations using in vitro human epidermal cells could help elucidate cellular and molecular processes in keratinocytes affected by arsenic. Data from such investigations could also provide the basis for developing cosmetic intervention for skin diseases caused by arsenic.

METHODS

The viability of HaCaT keratinocyte cultures with or without prior exposure to low-dose arsenic trioxide was compared for varying concentrations of arsenic trioxide over a time course of 14 days because in untreated control cultures, approximately 2 weeks is required to complete cell differentiation. Long-term cultures were established by culturing HaCaT cells on collagen IV, and cells were subsequently exposed to 0 parts per million (ppm), 1 ppm, 5 ppm, 7.5 ppm, 10 ppm, and 15 ppm of arsenic trioxide. The percentages of viable cells as well as DNA damage after exposure were determined on Day 2, Day 5, Day 8, and Day 14.

RESULTS

Using both statistical and visual analytics approaches for data analysis, we have observed a biphasic response at a 5 ppm dose with cell viability peaking on Day 8 in both chronic and acute exposures. Further, a low dose of 1 ppm arsenic trioxide enhanced HaCaT keratinocyte proliferation, whereas doses above 7.5 ppm inhibited growth.

CONCLUSION

The time course profiling of arsenic trioxide cytotoxicity using long-term HaCaT keratinocyte cultures presents an approach to modeling the human epidermal cellular responses to varying doses of arsenic trioxide treatment or exposure. A low dose of arsenic trioxide appears to aid cell growth but concomitantly disrupts the DNA transcription process.

Unfolded protein response signaling and MAP kinase pathways underlie pathogenesis of arsenic-induced cutaneous inflammation

Arsenic exposure through drinking water is a major global public health problem and is associated with an enhanced risk of various cancers including skin cancer. In human skin, arsenic induces precancerous melanosis and keratosis, which may progress to basal cell and squamous cell carcinoma. However, the mechanism by which these pathophysiologic alterations occur remains elusive. In this study, we showed that subchronic arsenic exposure to SKH-1 mice induced unfolded protein response (UPR) signaling regulated by proteins, inositol-requiring enzyme-1 (IRE1), PKR-like endoplasmic reticulum kinase (PERK) and activating transcription factor 6 (ATF6). Arsenic activated all three UPR regulatory proteins in the skin. Arsenic induced IRE1 phosphorylation which resulted in augmented splicing of X-box binding protein 1 (XBP-1) leading to its migration to the nucleus, and also enhanced transcriptional activation of downstream target proteins. Hyperphosphorylation of PERK which induces eukaryotic translation initial factor 2α (eIF2α) in a phosphorylation-dependent manner enhanced translation of ATF4, in addition to augmenting proteolytic activation of ATF6 in arsenic-treated skin. A similar increase in the expression of CHOP was observed. Enhanced XBP-1s, ATF4, and ATF6 regulated downstream chaperones GRP94 and GRP78. In addition, arsenic induced inflammation-related p38/MAPKAPK-2 MAPK signaling and alterations in Th-1/Th-2/Th-17 cytokines/chemokines and their receptors. Antioxidant N-acetyl cysteine blocked arsenic-induced reactive oxygen species, with a concomitant attenuation of UPR and mitogen-activated protein kinase (MAPK) signaling and proinflammatory cytokine/chemokine signatures. Our results identify novel pathways involved in the pathogenesis of arsenic-mediated cutaneous inflammation which may also be related to enhanced cancer risk in arsenic exposed cohorts.