Climate change and atopic dermatitis: is there a link?

The Impact of Air Pollution on Disease Activity in Bullous Pemphigoid and Pemphigus

With a growing awareness of climate change, air pollution has emerged as an important contributor to the development and exacerbation of inflammatory skin conditions. However, the effect of air pollution on immunobullous disease activity is unknown. In this study, we performed a retrospective cohort study of 115 patients with bullous pemphigoid and 152 patients with pemphigus from a university-based specialty clinic in the Southeastern United States. We compared standardized disease activity measures with inhalable particulate matter (particulate matter ≤2.5, particulate matter ≤10), ozone, atmospheric pollutants (sulphur dioxide, carbon monoxide, nitrogen dioxide), and air quality index. Results demonstrated small but statistically significant associations between Bullous Pemphigoid Disease Area Index total activity score and several variables (particulate matter ≤2.5, sulphur dioxide, and air quality index). In addition, there were small but significant negative correlations between ozone and bullous pemphigoid disease area index pruritus score as well as carbon monoxide and pemphigus disease area index score. This study suggests that air pollution may impact disease activity in bullous pemphigoid to a greater extent than pemphigus. Future studies should be aimed at identifying potential mechanisms for this association.

Environmental Impact of Dermatology and Action Towards It: A Narrative Review

There is a dual interplay between the environment and healthcare, which is associated with around 6% of global greenhouse gas (GHG) emissions, high water consumption, and large volumes of waste. Dermatology encompasses peculiarities such as the extensive use of topicals and cosmeceuticals, specific procedural treatments, and a wide range of activities spanning from dermatopathology to the use of biologicals. Some of these aspects might bear a significant environmental footprint, which has been characterized insufficiently until this point. According to recent data, the greatest share of overall GHG emissions associated with outpatient dermatology is purchased goods and services, followed by patient travel and waste, paralleling the health sector overall. To address these topics, six working groups on climate change or sustainability exist within the following dermatology associations: the American Academy of Dermatology (AAD), the Australasian College of Dermatologists (ACD), the British Association of Dermatologists (BAD), the European Academy of Dermatology and Venerology (EADV), the German Society of Dermatology (DDG), and the International Society of Dermatology (ISD). Member activities include scientific projects (original research and review articles, symposia in national conferences), provision of educational materials for trainees and peers, and advocacy. Dermatologists should be familiar with the environmental and climate impact of daily practice and use available resources for more information. At this time, a significant gap exists between individual sustainability efforts and the integration of these practices into policy. We propose to strengthen international collaborations within the field to provide more sustainable dermatological care.

Temporal and Topographical Heterogeneities in Clinical Manifestations of Atopic Dermatitis in China

Background/Objective: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by diverse clinical manifestations. However, variations in its clinical presentations across different ages, genders, anatomical sites, and seasons remain incompletely understood. The objective was to explore the clinical heterogeneities of AD using data from the Chinese non-selective registration system. Methods: A prospective analysis was conducted on 3829 AD patients enrolled in the Chinese Non-selective Registry for AD (CNRAD) at hospital settings from 2020 to 2022. Demographic profiles; distribution, type, and severity of the skin lesion; laboratory findings; allergic comorbidities; family history; and exacerbating factors were analyzed. Results: The male-to-female ratio was 0.92 among adolescent and adult AD patients but increased to 2.11 in elderly AD patients, highlighting an age-dependent gender difference in AD prevalence. Age groups displayed distinct anatomical preferences for lesion distribution, with reduced involvement of the cubital and popliteal fossae in adult and elderly patients. Based on skin lesion characteristics, ten clinical subtypes of AD were proposed. Elderly AD patients exhibited higher severity, compared to adolescence and adult AD patients, with male patients being more severe than females. Elderly AD patients showed a lower proportion of extrinsic type, compared to childhood AD patients. Seasonal change emerged as the most important factor triggering AD flares. Conclusions: This study provides new insights into the heterogeneities of AD clinical manifestations in the Chinese population, demonstrating their significant dependence on temporal factors, including age and season.

Preventing NLRP3 inflammasome activation: Therapeutic atrategy and challenges in atopic dermatitis

Atopic dermatitis (AD) is a prevalent inflammatory skin disorder characterized by its chronic, persistent, and recurrent nature. The pathophysiology of this condition is complex, involving various factors including cell-mediated immune responses, compromised skin barrier function, and alterations in hypersensitivity reactions. These components synergistically contribute to the perpetuation of the bothersome "itch-scratch-itch" cycle. Recent research has highlighted the significant role of the NLRP3 inflammasome in the development of AD and other inflammatory conditions. Current research indicates that the NLRP3 inflammasome plays a pivotal role in both the acute and chronic phases of AD by modulating the Th2/Th1 immune deviation. Moreover, the pharmacological suppression of NLRP3 has shown promising results in mitigating the pathological aspects of AD. This review outlines potential drug development strategies that target the NLRP3 inflammasome as a therapeutic approach for AD and the challenges faced in this endeavor.

Climate Change, Skin Health, and Dermatologic Disease: A Guide for the Dermatologist

Climate change has a pervasive impact on health and is of clinical relevance to every organ system. Climate change-related factors impact the skin's capacity to maintain homeostasis, leading to a variety of cutaneous diseases. Stratospheric ozone depletion has led to increased risk of melanoma and keratinocyte carcinomas due to ultraviolet radiation exposure. Atopic dermatitis, psoriasis, pemphigus, acne vulgaris, melasma, and photoaging are all associated with rising levels of air pollution. Elevated temperatures due to global warming induce disruption of the skin microbiome, thereby impacting atopic dermatitis, acne vulgaris, and psoriasis, and high temperatures are associated with exacerbation of skin disease and increased risk of heat stroke. Extreme weather events due to climate change, including floods and wildfires, are of relevance to the dermatologist as these events are implicated in cutaneous injuries, skin infections, and acute worsening of inflammatory skin disorders. The health consequences as well as the economic and social burden of climate change fall most heavily on vulnerable and marginalized populations due to structural disparities. As dermatologists, understanding the interaction of climate change and skin health is essential to appropriately manage dermatologic disease and advocate for our patients.

The impact of climate change on atopic dermatitis and mental health comorbidities: a review of the literature and examination of intersectionality

Climate change, fueled by increasing concentrations of greenhouse gases, is associated with rising temperatures, extreme weather events, increased aeroallergen production, and air pollution. Our understanding that many inflammatory cutaneous diseases carry important mental health comorbidities is expanding. Simultaneously, the detrimental impacts of climate change on human health are now widely recognized as a global public health crisis. Importantly, these climate-associated phenomena exacerbate the environmental triggers of atopic dermatitis (AD) and are also associated with amplification of comorbid mental health conditions in AD including depression, anxiety, trauma-related disorders, and psychotic spectrum disorders. This review is the first to examine the nexus of climate change, atopic dermatitis, and mental health comorbidities and emphasizes the disproportionate impacts of climate change in vulnerable and marginalized populations.

Climate change, the cutaneous microbiome and skin disease: implications for a warming world

The skin plays an important role in human health by providing barrier protection against environmental stressors. In addition to human skin cells, the cutaneous barrier is also home to a network of organisms that have co-evolved with humans, referred to as the cutaneous microbiome. This network has been demonstrated to play an active role in skin health and the manifestation of cutaneous disease. Here, we review how a warming world and its attendant changes in climatic variables, including temperature, humidity, ultraviolet radiation, and air pollution, influence the cutaneous microbiome and, in turn, skin health. Studies indicate that the cutaneous microbiome is affected by these factors, and these changes may influence the epidemiology and severity of cutaneous disorders including atopic dermatitis, acne vulgaris, psoriasis, and skin cancer. Further investigation into how the cutaneous microbiome changes in response to climate change and subsequently influences skin disease is needed to better anticipate future dermatologic needs and potentially generate novel therapeutic solutions in response.

Eczema-related Web Search Data in Sweden: Investigating Search Patterns and the Influence of Weather

As atopic eczema is triggered by environmental factors, such as temperature, differences in disease burden between and within countries are possible. One method to study this phenomenon is to perform web-search analysis, since the internet is commonly used to retrieve health-related information. This study, investigating the Google search volume regarding eczema in Swedish counties between April 2017 and March 2021, revealed a continuous increase in number of searches and that the search volume was higher in Northern than Southern Sweden. Gotland had the most searches per 100,000 inhabitants. In general, there was a negative correlation between search volume and temperature (r=-0.315, p < 0.001) and hours of sunshine (r=-0.213, p < 0.001), whereas there was a positive association between search volume and wind (r=0.229, p < 0.001). Search engine analysis is a rapid and cost-effective method of examining search behaviour regarding disease among the general population within a country and, thus, can enable the identification of regions with specific interests and needs.

Ambient temperature exposure and risk of outpatient visits for dermatologic diseases in Xinxiang, China: a time-series analysis

The effect of ambient temperature on dermatologic diseases has received widespread attention. Previous studies have shown that ambient temperature might affect specific dermatologic diseases, but results were inconsistent. This study aims to assess the short-term effect of ambient temperature on outpatient visits due to dermatologic diseases (DMs) in Xinxiang, China. Daily DMs outpatient visits, mean temperature, mean relative humidity, and air pollution data of Xinxiang were retrieved from January 1, 2015, to December 31, 2018. A distributed lag nonlinear model (DLNM) was applied to analyze the effect of ambient temperature on DMs outpatients. We controlled several potential confounding factors such as the long-term trend, public holiday, day of the week, humidity, and air pollutants (NO₂, PM_2.5). Finally, two more stratification analysis was conducted by age and gender. A total of 164,270 outpatients of DMs were enrolled during our study, and the daily mean visits were 113. The estimated effect of temperature on DMs was nonlinear. Heat temperature would exacerbate outpatients of dermatologic diseases. With a reference median temperature (17 °C), the effect of temperature on DMs was most pronounced at lag0-14; exposure to heat (32 °C, 99th) was associated with 1.565 (95% CI: 1.266-1.934) increased risk of outpatients for DMs. Stratification analysis showed that citizens of young ages were susceptive to heat; both genders had a similar relationship between temperature and DMs risk. This study highlights that ambient temperature was associated with DMs outpatients; heat temperature might aggravate DMs risk. The health hazards of heat temperature required more attention, and more effective prevention measurements should be designed and implemented to curb global warming.

Effects of ambient temperature on outpatient visits for dermatitis in Xinxiang, China: a time-series analysis

Previous studies have reported regional variations in the relationship between ambient temperature and dermatitis, which therefore remain inconclusive. This study aimed to understand the short-term effects of ambient temperature in outpatients with dermatitis in Xinxiang. Routine data of dermatitis outpatient visits between January 1, 2015, and December 31, 2018 were acquired from the First Affiliated Hospital of Xinxiang Medical University. A distributed lag nonlinear model (DLNM) in combination with a generalized additive model (GAM) was applied to investigate the acute impact of ambient temperature on dermatitis outpatients. Two stratified analyses based on age and sex were conducted to explore their potential modification effects. A total of 18,064 dermatitis outpatient records were retrieved during the study period. The relationship between ambient temperature and dermatitis outpatients was found to be nonlinear; exposure-response curves were approximately "J" shaped. The risk of dermatitis outpatient increased with a corresponding elevation in temperature from 11.5 to 27.5°C. However, the significance was lost when the temperature exceeded the given range. Stratified analysis demonstrated higher sensitivity to temperature in females than in males, and the young groups (<15 years) might be sensitive to heat temperature. This study provides first-hand epidemiological evidence demonstrating a higher risk of dermatitis outpatient visits associated with moderately higher temperatures. The outcomes of this study create awareness among citizens to take the necessary precautions to prevent the adverse effects of moderate heat temperature during early summer and autumn seasons.

Can crowdsourced data help to optimize atopic dermatitis treatment? Comparing web search data and environmental data in Germany

BACKGROUND

Atopic dermatitis (AD) is one of the most common chronic skin diseases worldwide, showing various manifestations and having a severe impact on quality of life. As previous studies demonstrated, internet search analysis can help identify public interest in diseases and possible influencing factors on search behavior.

OBJECTIVE

To identify AD-related topics of interest in Germany using internet search volume.

METHODS

Google Ads Keyword Planner was used to identify AD-related search terms including their search volume in Germany on a national level as well as in 16 selected cities from January 2016 to December 2019. Identified keywords were qualitatively analyzed, and temporal trends as well as the influence of seasonal and environmental factors on search volume were assessed.

RESULTS

Overall, 1222 AD-related search terms with a search volume of 8 842 360 searches were identified. An increase from 2016 to 2019 and seasonal peaks from January to April of each year were observed. Nationwide, the search volume correlated with mean monthly temperature and sun duration. With increasing temperature and sun duration, a significant decrease in search queries was observed. The most populated cities showed the lowest number of searches per 100 000 inhabitants (Berlin, Hamburg, and Munich). In the eight categories formed (comorbidities, general, influential factors, localization, stage of life, symptoms/severity, therapy/information, and questions on AD), the highest proportion of search queries were assigned to the category "therapy/information" in most cities. In this category, a focus on the topics of "alternative medicine" and "home remedies" could be observed.

CONCLUSION

The overall high and increasing search volume indicates a high interest in AD-related topics, especially regarding treatment and disease education. Information provided by internet search volume analyses can optimize AD therapy and patient-centered care by providing insight into patient needs and predicting potential climatic trigger factors.

Comorbidities and Environmental Factors Associated with Atopic Dermatitis in Children and Adults in Dermatology-Venereology in Cotonou, Benin

Introduction

The objective of this work was to document the comorbidities and environmental factors associated with atopic dermatitis (AD) in dermatology Venereology in Cotonou.

Methods

A cross-sectional, prospective, and analytical study included, from January 2016 to December 2018, in the Dermatology-Venereology Department of the National Teaching Hospital Hubert Koutoukou Maga (CNHU-HKM) of Cotonou, children and adults after free and informed consent, in whom the diagnosis of AD was retained according to the criteria of the United Kingdom Working Party. Severity was assessed using SCORAD (severity scoring of atopic dermatitis).

Results

The overall prevalence of AD was 7.7%. AD was more frequent in children (56.8% and 40.6%) and adults (59.8% and 37.4%) from urban and periurban areas (0.003 < p < 0.034). It was more frequent in children who regularly dewormed and those with complete vaccination (0.001 < p < 0.01). In 54.8% of children and 58.9% of adults, flare-ups occurred during the warm season. The main associated comorbidities were rhinitis and conjunctivitis in both children (49.7% and 36.1%, respectively) and adults (32.7% and 26.2%, respectively). The main triggering factors in children were heat (43.2%), pneumallergens (28.4%), and skin irritants (22.6%). In adults, we noted skin irritants (58.9%), heat (47.7%), and psychological factors (34.6%). In adults, the use of detergent soaps was associated with lichenified and severe AD (0.003 < p < 0.006) and that of lightening soaps with acute AD (p=0.042).

Conclusion

AD in the Dermatology-Venereology Department of the CNHU-HKM of Cotonou was associated with comorbidities. It was influenced by environmental factors related to the tropical climate and by skin irritants or allergens.

Addressing Climate-Related Health Impacts During the Patient Encounter: A Practical Guide for Pediatric Dermatologists

Pediatric populations are expected to bear most of the climate change impacts, with racial minorities and children living in poorer countries being particularly vulnerable. Given their relevance to cutaneous disease, dermatologists should be aware of these climate-sensitive health impacts and the ways in which they intersect with social factors. Strategies including targeted risk communication, motivational interviewing, and storytelling can help facilitate climate discussions during the patient encounter. In this article the authors summarize common dermatologic health impacts related to environmental exposures and provide sample scripts for climate messaging.

Climate Change and Global Issues in Allergy and Immunology

The steady increase in global temperatures, resulting from the combustion of fossil fuels and the accumulation of greenhouse gases (GHG), continues to destabilize all ecosystems worldwide. Although annual emissions must halve by 2030 and reach net-zero by 2050 to limit some of the most catastrophic impacts associated with a warming planet, the world's efforts to curb GHG emissions fall short of the commitments made in the 2015 Paris Agreement (1). To this effect, July 2021 was recently declared the hottest month ever recorded in 142 years (2). The ramifications of these changes on global temperatures are complex and further promote outdoor air pollution, pollen exposure, and extreme weather events. Besides worsening respiratory health, air pollution, promotes atopy and susceptibility to infections. The GHG effects on pollen affect the frequency and severity of asthma and allergic rhinitis. Changes in temperature, air pollution, and extreme weather events exert adverse multisystemic health effects and disproportionally affect disadvantaged and vulnerable populations. This article is an update for allergists and immunologists about the health impacts of climate change, already evident in our daily practices. It is also a call to action and advocacy, including integrating climate change-related mitigation, education, and adaptation measures to protect our patients and avert further injury to our planet.

The Role of the Environment and Exposome in Atopic Dermatitis

PURPOSE OF REVIEW

Atopic dermatitis (AD) is a chronic inflammatory skin disorder affecting up to 20% of children and up to 5% of adults worldwide, contributing to significant disease-related morbidity in this patient cohort. Its aetiopathogenesis is underpinned by multiple factors, including genetic susceptibility, skin barrier defects, a skewed cutaneous immune response and microbiome perturbation in both the skin and the gut. In this review, we aim to examine the biological effects of key environmental exposures (the sum of which is termed the "exposome") at the population, community and individual levels in order to describe their effect on AD pathogenesis.

RECENT FINDINGS

It is now understood that as well as considering the type of environmental exposure with regard to its effect on AD pathogenesis, the dosage and timing of the exposure are both critical domains that may lead to either exacerbation or amelioration of disease. In this review, we consider the effects of population-wide exposures such as climate change, migration and urbanization; community-specific exposures such as air pollution, water hardness and allergic sensitisation; and individual factors such as diet, microbiome alteration, psychosocial stress and the impact of topical and systemic therapy.

SUMMARY

This review summarises the interaction of the above environmental factors with the other domains of AD pathogenesis, namely, the inherent genetic defects, the skin barrier, the immune system and the cutaneous and gut microbiota. We specifically emphasise the timing and dosage of exposures and its effect on the cellular and molecular pathways implicated in AD.

Short-Term Exposure to Ambient Air Pollution and Increased Emergency Room Visits for Skin Diseases in Beijing, China

Skin diseases have become a global concern. This study aims to evaluate the associations between ambient air pollution and emergency room visits for skin diseases under the background of improving air quality in China. Based on 45,094 cases from a general hospital and fixed-site monitoring environmental data from 2014–2019 in Beijing, China, this study used generalized additive models with quasi-Poisson regression to estimate the exposure–health associations at lag 0–1 to lag 0–7. PM_2.5 and NO₂ exposure were associated with increased emergency room visits for total skin diseases (ICD10: L00-L99). Positive associations of PM_2.5, PM₁₀, O₃ and NO₂ with dermatitis/eczema (ICD-10: L20–30), as well as SO₂ and NO₂ with urticaria (ICD-10: L50) visits were also found. For instance, a 10 μg/m³ increase in PM_2.5 was associated with increases of 0.7% (95%CI: 0.2%, 1.2%) in total skin diseases visits at lag 0–5 and 1.1% (95%CI: 0.6%, 1.7%) in dermatitis/eczema visits at lag 0–1, respectively. For PM_2.5, PM₁₀ and CO, stronger annual associations were typically observed in the high-pollution (2014) and low-pollution (2018/2019) years. For instance, a 10 μg/m³ increase in PM_2.5 at lag 0–5 was associated with increases of 1.8% (95%CI: 1.0%, 2.6%) and 2.3% (95%CI: 0.4%, 4.3%) in total skin disease visits in 2014 and 2018, respectively. Our study emphasizes the necessity of controlling the potential health hazard of air pollutants on skin, although significant achievements in air quality control have been made in China.

Climate change and dermatology: An introduction to a special topic, for this special issue

Anthropogenic global climate change is a well-documented phenomenon that has led to average global temperatures climbing to approximately 1 °C above preindustrial (1850-1900) levels, with even higher regional deviations in some areas and significantly increased average warming in densely populated urban centers. In 2018, the United Nations Intergovernmental Panel on Climate Change set a threshold of 1.5 °C of average warming (above the preindustrial baseline), beyond which our planet will become significantly less hospitable to human life. However, adverse human health impacts are already occurring due to current levels of global climate change, as summarized by publications such as The Lancet's annual "Countdown on Health and Climate Change," initiated in 2016. The human health impacts of climate change are truly cross-disciplinary, with nearly every medical specialty either already facing or set to face effects. The field of dermatology is not immune to these risks. This special issue of the International Journal of Women's Dermatology is dedicated to the cross section of dermatology and climate change. This initial article will serve as an overview to introduce readers to the topic and to lay the groundwork for the rest of the issue. We are delighted to work with the Women's Dermatological Society and welcome their support for this dedicated issue. Herein, you will read from up-and-coming stars in the field and established experts, including articles on the following key areas: infectious diseases, environmentally friendly office practices, sunscreens and the environment, refugee health, heat-related illness, the effect of air pollution on the skin, the impact of climate change on pediatric dermatology, implications for skin cancer, and skin issues related to flooding and extreme weather events.

Climate Change and Inpatient Dermatology

PURPOSE OF REVIEW

Climate change represents a major existential threat facing the global community, and it has already begun to affect human health in a multitude of ways. This review highlights and discusses the implications that climate change has already had and is expected to have for inpatient dermatologists.

RECENT FINDINGS

There are a variety of conditions affected by climate changes. The distribution and frequencies of infectious diseases and their vectors are changing in line with variations in climate conditions. Increased temperatures have already been associated with exacerbation of existing skin conditions, such as atopic dermatitis, and recent evidence suggests that higher temperatures will also magnify the effects of harmful ultraviolet radiation. Extreme weather events that result from climate change are followed by an array of dermatologic conditions that may be unusual for the given location. Inpatient dermatologists should be prepared to manage these potentially unfamiliar dermatologic consequences of climate change.

SUMMARY

Climate change will have widespread effects on the medical field, and inpatient dermatologists will be faced with their own unique set of challenges and practice variations. Practitioners should be familiar with the ongoing and predicted effects of climate change in their locations so that they can readily identify and treat associated conditions, and they should adjust their practice to reduce their carbon footprint and serve as a model for patients to do the same.

Climate change and pediatric skin health

Children are known to disproportionately bear the health impacts of climate change, particularly children living in impoverished areas. Owing to their developing physiology and immature metabolism, distinct exposure behaviors, and reliance on adults for care and protection, children are uniquely susceptible to the adverse effects of our warming planet. Herein, we summarize the known impacts of climate change on pediatric skin health, including its effects on atopic dermatitis, vector-borne and other infectious diseases, nutritional deficiencies, and psychodermatoses.

Evaluation of factors that may affect disease development and severity in childhood atopic dermatitis

BACKGROUND

Atopic dermatitis is a chronic, relapsing, inflammatory disease. Data concerning the role of perinatal conditions in the development of the disease are few and inconsistent. The purpose of this study was to investigate the effects of skin care on the severity of the disease, also to evaluate the relations of perinatal conditions with disease development and severity.

METHODS

Seventy-five patients with atopic dermatitis aged 2-10 years, their parents and 65 healthy age-compatible volunteers and their parents were included in the study. The Scoring Atopic Dermatitis (SCORAD) score was used to assess the severity of the disease.

RESULTS

Emollient use (regular/irregular) was higher in patients with severe disease compared to those with mild and moderate disease, but no significant difference was determined in regular use rates (P=0.029, and P=0.504, respectively). Topical corticosteroid use and sleep disturbance rates in the previous three months in the subjects regularly using emollients were low (P=0.032, and P=0.005, respectively). The incidence of severe disease was higher in the patients born in the winter (P=0.033). Severe disease rates were significantly high in the subjects in the patient group with advanced maternal age, a history of cesarean delivery and incubator use (P=0.017, P=0.046, and P=0.025, respectively).

CONCLUSIONS

Low topical corticosteroid requirement and sleep disturbance rates in the subjects regularly using moisturizers emphasize the importance of emollient use in treatment. The association of cesarean delivery, history of incubator, and birth in winter with severe disease suggests that disease severity is related to less exposure to environmental allergens in the hygiene hypothesis.

The Role of the Environmental Risk Factors in the Pathogenesis and Clinical Outcome of Atopic Dermatitis

Atopic dermatitis (AD) prevalence is rising worldwide. Literature data suggest the incidence of AD in developing countries is gradually getting close to that of developed ones, in which AD affects 20% of the paediatric population. Such an increment, associated with significant variations in prevalence among the various countries, underlines the importance of environmental factors in the disease onset. Among these, great importance is given to hygiene, intestinal microbiota, exposure to bacterial endotoxins, outdoor living with contact to animals, atmospheric pollution, weather, and diet. Genetic (alteration of the skin barrier function) as well as immunologic factors concur with the environmental ones. Only the systematical study of all these elements can best elucidate AD epidemiology.