Impact of Air Pollution on Atopic Dermatitis: A Comprehensive Review

Metabolite analysis of 14C-labeled chloromethylisothiazolinone/methylisothiazolinone for toxicological consideration of inhaled isothiazolinone biocides in lungs

5-Chloro-2-methyl-4-isothiazolin-3-one (CMIT) and 2-methyl-4-isothiazolin-3-one (MIT) used as preservatives in various products, including humidifier disinfectants, presents substantial health hazards. This research delves into the toxicological assessments of CMIT/MIT in the respiratory system using animal models. Through the synthesis of radiolabeled [14C]CMIT and [14C]MIT, we investigated the biological uptake and in vivo behaviors of CMIT/MIT in the respiratory tissues following intratracheal exposure. Quantitative whole-body autoradiography (QWBA) revealed significant persistence of CMIT/MIT in lung tissue. In addition, radio high-performance liquid chromatography (radio-HPLC) with tandem mass spectrometry (LC-MS/MS) was employed for metabolite profiling and identification. Notably, around 28% of the radiolabel was retained in tissue after the extraction step, suggesting covalent binding of CMIT/MIT and their metabolites with pulmonary biomolecules. This observation demonstrates the propensity of the electrophilic isothiazolinone ring in CMIT/MIT to undergo chemical interactions with biothiols in proteins and enzymes, fostering irreversible alterations of biomolecules. Such accumulations of transformations could result in direct toxicity at both cellular and organ levels. Additionally, the detection of metabolites, including a MIT dimer conjugated with glutathione (GSH), as analyzed by mass spectrometry indicates the possible reduction of cellular GSH levels and subsequent oxidative stress. This investigation offers an in-depth insight into the toxic mechanisms of CMIT/MIT, underlying their capability to engage in complex formations with biomacromolecules and induce pronounced respiratory toxicity. These results highlight the imperative for stringent safety assessments of these chemicals, advocating for improved public health and safety measures in the use of chemicals.

Is short-term exposure to primary gaseous air pollutants associated with AIDS-related deaths? Evidence from a time-stratified case-crossover study

Primary gaseous air pollutants have been associated with death from multiple causes, however, it remains unknown if they play a role in premature mortality among individuals living with HIV/AIDS. Data on HIV/AIDS patients were collected from the Hubei Provincial Center for Disease Control and Prevention, with a total of 1,467 AIDS-related deaths (ARD) between 2013 and 2020. Daily mean sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were generated by artificial intelligence algorithms combined with big data. We employed a time-stratified case-crossover approach and conditional logistical regression models to investigate the acute effects of primary gaseous air pollutants on ARD. Per interquartile range increase in the concentrations of SO2 was significantly linked with ARD, with a corresponding odds ratio (OR) of 1.17 [95% confidence intervals (CIs): 1.01, 1.35] at lag 4 day. Furthermore, our findings indicated that males exhibited a heightened vulnerability to the adverse effects of SO2 and NO2, for example, the ORs were 1.24 (95% CIs: 1.05, 1.47) and 1.16 (95% CIs: 1.01, 1.34), respectively. Moreover, individuals aged over 65 years were more susceptible to SO2 and CO. Additionally, we identified the warm season as a sensitive period for mortality associated with SO2 and NO2. Our study furnished fresh evidence regarding the detrimental effects of primary gaseous air pollutants on ARD.

Nanotopology-Enabled On-Site Pathogen Detection for Managing Atopic Dermatitis

Atopic dermatitis (AD), a prevalent skin condition often complicated by microbial infection, poses a significant challenge in identifying the responsible pathogen for its effective management. However, a reliable, safe tool for pinpointing the source of these infections remains elusive. In this study, a novel on-site pathogen detection that combines chemically functionalized nanotopology with genetic analysis is proposed to capture and analyze pathogens closely associated with severe atopic dermatitis. The chemically functionalized nanotopology features a 3D hierarchical nanopillar array (HNA) with a functional polymer coating, tailored to isolate target pathogens from infected skin. This innovative nanotopology demonstrates superior pathogenic capture efficiency, favorable entrapment patterns, and non-cytotoxicity. An HNA-assembled stick is utilized to directly retrieve bacteria from infected skin samples, followed by extraction-free quantitative loop-mediated isothermal amplification (direct qLAMP) for validation. To mimic human skin conditions, porcine skin is employed to successfully capture Staphylococcus aureus, a common bacterium exacerbating AD cases. The on-site detection method exhibits an impressive detection limit of 103 cells mL-1. The HNA-assembled stick represents a promising tool for on-site detection of bacteria associated with atopic dermatitis. This innovative approach enables to deepen the understanding of AD pathogenesis and open avenues for more effective management strategies for chronic skin conditions.

Impact of climate change on atopic dermatitis: A review by the International Eczema Council

Atopic dermatitis (AD), the most burdensome skin condition worldwide, is influenced by climatic factors and air pollution; however, the impact of increasing climatic hazards on AD remains poorly characterized. Leveraging an existing framework for 10 climatic hazards related to greenhouse gas emissions, we identified 18 studies with evidence for an impact on AD through a systematic search. Most climatic hazards had evidence for aggravation of AD the impact ranged from direct effects like particulate matter-induced AD exacerbations from wildfires to the potential for indirect effects like drought-induced food insecurity and migration. We then created maps comparing the past, present, and future projected burden of climatic hazards to global AD prevalence data. Data are lacking, especially from those regions most likely to experience more climatic hazards. We highlight gaps important for future research: understanding the synergistic impacts of climatic hazards on AD, long-term disease activity, the differential impact on vulnerable populations, and how basic mechanisms explain population-level trends.

National prevalence of atopic dermatitis in Korean adolescents from 2009 to 2022

Previous studies have examined the prevalence of allergic diseases in adolescents 1-2 years after the emergence of the COVID-19 pandemic. However, more data is needed to understand the long-term impact of COVID-19 on allergic diseases. Thus, we aimed to examine the trend of the atopic dermatitis prevalence in Korean adolescents before and during the COVID-19 pandemic across 14 years. Additionally, we analyze the risk factors of atopic dermatitis (AD) based on the results. The Korean Disease Control and Prevention Agency conducted the Korea Youth Risk Behavior Web-based Survey from 2009 to 2022, from which the data for this study were obtained. Prevalence trends were compared across subgroups, and the β difference (βdiff) was calculated. We computed odds ratios to examine changes in the disease prevalence before and during the pandemic. This study included a total of 917,461 participants from 2009 to 2022. The prevalence of atopic dermatitis increased from 6.79% (95% CI 6.66-6.91) in 2009-2011 to 6.89% (95% CI 6.72-7.05) in 2018-2019, then decreased slightly to 5.82% (95% CI 5.60-6.04) in 2022. Across the 14 years, middle school student status, low parent's highest education level, low household income, non-alcohol consumption, non-smoker smoking status, no suicidal thoughts, and no suicide attempts were associated with increased risk of atopic dermatitis, while female sex, rural residence, high BMI, low school performance, low household income, and no feelings of sadness and despair was associated with a small increase. This study examined the prevalence of atopic dermatitis across an 18-year, and found that the prevalence increased in the pre-pandemic then decreased during the start of the pandemic and remained constant throughout the pandemic. This trend could be explained mainly by the large scale social and political changes that occurred during the COVID-19 pandemic.

Human Keratinocyte Responses to Woodsmoke Chemicals

Air pollution consists of complex mixtures of chemicals with serious deleterious health effects from acute and chronic exposure. To help understand the mechanisms by which adverse effects occur, the present work examines the responses of cultured human epidermal keratinocytes to specific chemicals commonly found in woodsmoke. Our earlier findings with liquid smoke flavoring (aqueous extract of charred wood) revealed that such extracts stimulated the expression of genes associated with oxidative stress and proinflammatory response, activated the aryl hydrocarbon receptor, thereby inducing cytochrome P4501A1 activity, and induced cross-linked envelope formation, a lethal event ordinarily occurring during terminal differentiation. The present results showed that furfural produced transcriptional responses resembling those of liquid smoke, cyclohexanedione activated the aryl hydrocarbon receptor, and several chemicals induced envelope formation. Of these, syringol permeabilized the cells to the egress of lactate dehydrogenase at a concentration close to that yielding envelope formation, while furfural induced envelope formation without permeabilization detectable in this way. Furfural (but not syringol) stimulated the incorporation of amines into cell proteins in extracts in the absence of transglutaminase activity. Nevertheless, both chemicals substantially increased the amount of cellular protein incorporated into envelopes and greatly altered the envelope protein profile. Moreover, the proportion of keratin in the envelopes was dramatically increased. These findings are consistent with the chemically induced protein cross-linking in the cells. Elucidating mechanisms by which this phenomenon occurs may help understand how smoke chemicals interact with proteins to elicit cellular responses, interpret bioassays of complex pollutant mixtures, and suggest additional sensitive ways to monitor exposures.

Study on the Transport Properties of SO2 and NO at the Interface of H2O2 Solutions Using Molecular Dynamics

Gas-liquid interfaces have a unique structure different from the bulk phase due to the complex intermolecular interactions within them and are regarded as barriers that prevent gases from entering solution or as channels that affect gas reactions. In this study, the adsorption and mass-transfer mechanisms of sulfur dioxide and nitric oxide at the gas-liquid interface of a H2O2 solution were comprehensively analyzed using molecular dynamics (MD) simulations. The analysis on molecule angle showed that H2O molecules tended to align parallel to the solution surface on the surface of the H2O2 solution. Regardless of whether the gas was adsorbed on the surface of the solution or not, H2O2 molecules were always perpendicular to the interface of the solution. The analysis on molecule angle and radial distribution function revealed that the H atoms of H2O molecules had a corresponding turn, and SO2 molecules were greatly affected by the attraction of H2O2 molecules during the adsorption of gas molecules on the interface. Steered MD was utilized to investigate the mass-transfer process of SO2 and NO molecules across the gas-liquid interface. The S atoms of SO2 molecules were significantly influenced by H2O2 molecules, while the O atoms of NO molecules gradually transitioned from the gas phase to the liquid phase. The results provided information on how gas molecules interacted with the surface of the solution and the specific details of the molecular orientation at the solution surface.

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

Factors by which global warming worsens allergic disease

Increased use of fossil fuels has led to global warming with concomitant increases in the severity and frequency of extreme weather events such as wildfires and sand and dust storms. These changes have led to increases in air pollutants such as particulate matter and greenhouse gases. Global warming is also associated with increases in pollen season length and pollen concentration. Particulate matter, greenhouse gases, and pollen synergistically increase the incidence and severity of allergic diseases. Other indirect factors such as droughts, flooding, thunderstorms, heat waves, water pollution, human migration, deforestation, loss of green space, and decreasing biodiversity (including microbial diversity) also affect the incidence and severity of allergic disease. Global warming and extreme weather events are expected to increase in the coming decades, and further increases in allergic diseases are expected, exacerbating the already high health care burden associated with these diseases. There is an urgent need to mitigate and adapt to the effects of climate change to improve human health. Human health and planetary health are connected and the concept of One Health, which is an integrated, unifying approach to balance and optimize the health of people, animals, and the environment needs to be emphasized. Clinicians are trusted members of the community, and they need to take a strong leadership role in educating patients on climate change and its adverse effects on human health. They also need to advocate for policy changes that decrease the use of fossil fuels and increase biodiversity and green space to enable a healthier and more sustainable future.

Global warming and implications for epithelial barrier disruption and respiratory and dermatologic allergic diseases

Global warming has direct and indirect effects, as well as short- and long-term impacts on the respiratory and skin barriers. Extreme temperature directly affects the airway epithelial barrier by disrupting the structural proteins and by triggering airway inflammation and hyperreactivity. It enhances tidal volume and respiratory rate by affecting the thermoregulatory system, causing specific airway resistance and reflex bronchoconstriction via activation of bronchopulmonary vagal C fibers and upregulation of transient receptor potential vanilloid (TRPV) 1 and TRPV4. Heat shock proteins are activated under heat stress and contribute to both epithelial barrier dysfunction and airway inflammation. Accordingly, the frequency and severity of allergic rhinitis and asthma have been increasing. Heat activates TRPV3 in keratinocytes, causing the secretion of inflammatory mediators and eventually pruritus. Exposure to air pollutants alters the expression of genes that control skin barrier integrity and triggers an immune response, increasing the incidence and prevalence of atopic dermatitis. There is evidence that extreme temperature, heavy rains and floods, air pollution, and wildfires increase atopic dermatitis flares. In this narrative review, focused on the last 3 years of literature, we explore the effects of global warming on respiratory and skin barrier and their clinical consequences.

Coffea arabica Extract Attenuates Atopic Dermatitis-like Skin Lesions by Regulating NLRP3 Inflammasome Expression and Skin Barrier Functions

Atopic dermatitis (AD) is a common skin disease worldwide. The major causes of AD are skin barrier defects, immune dysfunction, and oxidative stress. In this study, we investigated the anti-oxidation and anti-inflammation effects of Coffea arabica extract (CAE) and its regulation of the skin barrier and immune functions in AD. In vitro experiments revealed that CAE decreased the reactive oxygen species levels and inhibited the translocation of nuclear factor-κB (NF-κB), further reducing the secretion of interleukin (IL)-1β and IL-6 induced by interferon-γ (IFN-γ)/tumor necrosis factor-α (TNF-α). Moreover, CAE decreased IFN-γ/TNF-α-induced NLR family pyrin domain-containing 3 (NLRP3), caspase-1, high-mobility group box 1 (HMGB1), and receptor for advanced glycation end products (RAGE) expression levels. It also restored the protein levels of skin barrier function-related markers including filaggrin and claudin-1. In vivo experiments revealed that CAE not only reduced the redness of the backs of mice caused by 2,4-dinitrochlorobenzene (DNCB) but also reduced the levels of pro-inflammatory factors in their skin. CAE also reduced transepidermal water loss (TEWL) and immune cell infiltration in DNCB-treated mice. Overall, CAE exerted anti-oxidation and anti-inflammation effects and ameliorated skin barrier dysfunction, suggesting its potential as an active ingredient for AD treatment.

Oxidative Stress Status and Its Relationship to Skin Aging

Skin and cellular aging are impacted by various toxins in our environment such as air pollution, water contamination, an increased prevalence of light-emitting diodes, electromagnetic frequencies, various yeast and other fungi, parasitic infections, and mold and heavy metal toxicity. Basic topical skin care is insufficient to adequately protect an individual's integumentary system and other organs from these types of daily cellular stressors. These stressors impact the level of oxidative stressstatus (OSS). OSS is measurable through biomarker analysis of various body fluids including blood, saliva, urine, and breath. This poses a unique assessment challenge for aesthetic practitioners as the OSS of a patient impacts their overall aging process. Aesthetic practitioners observe the aging process through visual assessment of a patient's skin quality, skin barrier function, and the presence of solar lentigines, erythema, edema, telangiectasia, loss of collagen and elastin, bone density, and redistribution of subcutaneous tissue. Mitigating a patient's daily exposure to OS and its impacts on the skin, other organ tissues, and metabolism poses a unique challenge in medical aesthetic treatment planning. For this reason, the use of stem cells and exosomes is gaining popularity in aesthetic medicine. The purpose of this literature review is to highlight currently available research, applications, limitations, and mitigation strategies in reducing OSS on the integumentary system and aging processes.

Environmental Air Pollutants Affecting Skin Functions with Systemic Implications

The increase in air pollution worldwide represents an environmental risk factor that has global implications for the health of humans worldwide. The skin of billions of people is exposed to a mixture of harmful air pollutants, which can affect its physiology and are responsible for cutaneous damage. Some polycyclic aromatic hydrocarbons are photoreactive and could be activated by ultraviolet radiation (UVR). Therefore, such UVR exposure would enhance their deleterious effects on the skin. Air pollution also affects vitamin D synthesis by reducing UVB radiation, which is essential for the production of vitamin D3, tachysterol, and lumisterol derivatives. Ambient air pollutants, photopollution, blue-light pollution, and cigarette smoke compromise cutaneous structural integrity, can interact with human skin microbiota, and trigger or exacerbate a range of skin diseases through various mechanisms. Generally, air pollution elicits an oxidative stress response on the skin that can activate the inflammatory responses. The aryl hydrocarbon receptor (AhR) can act as a sensor for small molecules such as air pollutants and plays a crucial role in responses to (photo)pollution. On the other hand, targeting AhR/Nrf2 is emerging as a novel treatment option for air pollutants that induce or exacerbate inflammatory skin diseases. Therefore, AhR with downstream regulatory pathways would represent a crucial signaling system regulating the skin phenotype in a Yin and Yang fashion defined by the chemical nature of the activating factor and the cellular and tissue context.