Eczema, facial erythema, and seborrheic dermatitis symptoms among young adults in China in relation to ambient air pollution, climate, and home environment

Global, regional, and national burden of seborrheic dermatitis in individuals aged 55 and older from 1990 to 2021: a trend analysis and future projections

Seborrheic dermatitis (SD), an inflammatory dermatosis, significantly lowers quality of life, particularly in the elderly. Although studies have focused on the burden of SD globally before, trends among people 55 and older have received less attention. Utilizing the data released in 2021 by the Global Burden of Disease (GBD) consortium, our research was conducted to evaluate the global, regional, and national burden of SD in adults over 55 between 1990 and 2021 through incidence, prevalence, and disability-adjusted life years (DALYs) alongside advanced methods such as joinpoint regression analysis. We also performed decomposition analysis to examine the contributions of population and epidemiological changes. Correlation analysis was used to explore the assocaition between Socio-demographic Index (SDI) /climate-related parameters and SD. The global incidence of SD among adults aged 55 and older markedly rose from 1990 to 2021. The incidence grew by 120.84%, the prevalence by 125.09%, and the DALYs rose by 124.25%. Higher burdens were observed in the high and high-middle SDI regions, whereas low SDI areas displayed the highest age-standardized rates. Environmental factors, particularly global warming, were strongly connected with the incidence and prevalence of SD. Future projections suggested continued increases in SD cases through 2040. This study highlights the increasing burden of SD among older adults, emphasizing the role of demographic and environmental factors. Targeted public health interventions addressing aging populations and climate-related risks are urgent to mitigate the impact of SD globally.

Is seborrhoeic dermatitis of infancy and childhood related to maternal history of seborrhoeic dermatitis? A large population-based cohort study from the UK

BACKGROUND

The pathophysiology of seborrhoeic dermatitis (SebD) is complex and is likely to be related to an interplay of the microbial colonization of the skin and local immunity. There are also genetic components to the illness. At least two forms of SebD exist, infantile (ISebD), which has onset early in life, and SebD with later onset.

OBJECTIVES

We aimed to improve our understanding of SebD by evaluating whether maternal history of SebD is associated with increased risk of ISebD or childhood-onset SebD (CSebD, with onset after 5 years of life).

METHODS

We performed a prospective cohort study of mother-child pairs using data from a large UK primary care electronic medical records database.

RESULTS

We analysed 1 023 140 children with linked maternal data. The mean (SD) time of follow-up for the children was 10.2 (7.9) years for a total follow-up of more than 10 million person-years. Proportional hazards models [HRs (95% confidence intervals)] were used to examine the association between presence of SebD in mothers and SebD in the child. Maternal history of SebD was associated with development of SebD [1.99 (1.91-2.09)], ISebD [1.86 (1.74-1.99)] and CSebD [2.12 (1.97-2.29)] in their children. However, ISebD in a child was not associated with that child later developing CSebD [0.91 (0.82-1.01)].

CONCLUSIONS

Maternal history of SebD is a risk factor for the development of SebD in children. While we cannot fully differentiate SebD risk due to mother's genetics (inheritance) from a newborn's environment, our results lend credence to the possible role of genetics in SebD. A child with ISebD does not appear to be at risk for developing CSebD.

Perturbations in the skin microbiome of infantile and adult seborrheic dermatitis and new treatment options based on restoring a healthy skin microbiome

Seborrheic dermatitis (SD) is a common, multifaceted skin condition, but its undefined etiology hampers the development of effective therapeutic strategies. In this review, we describe the intricate relationship between the skin microbiome and the pathogenesis of SD, focusing on the complex interplay between three major groups of organisms that can either induce inflammation (Malassezia spp., Staphylococcus aureus) or else promote healthy skin (Propionibacterium spp.). We describe how the disequilibrium of these microorganisms in the skin microbiome can develop skin inflammation in SD patients. Understanding these complex interactions of the skin microbiome has led to development of novel probiotics (e.g., Vitreoscilla spp. and Lactobacillus spp.) to restore normal skin physiology in SD. There are also differences in the skin microbiomes of healthy and SD infant and adult patients that impact pathogenesis and prompt different management strategies. A deeper understanding of the skin microbiome and its dynamic interactions will provide valuable insights into the pathogenesis of SD and prompt further development of targeted probiotic treatments to restore the balance of the skin microbiome in SD patients.

Patient and Healthcare Provider Perspectives on Disease Burden of Seborrheic Dermatitis in the United States: Results from a National Survey

INTRODUCTION

Seborrheic dermatitis (SD) is a common, chronic inflammatory skin disease, but the physical and emotional burden of patients with SD experience has not been well characterized.

METHODS

The Harris Poll conducted online surveys of US patients and healthcare providers (HCPs) from December 2021 to January 2022.

RESULTS

Almost half of patients reported that SD negatively impacts their emotional and physical well-being "a lot/a great deal"; HCPs underestimate the level of impact on patients. Most patients with SD reported a significant mental health impact, including anxiety, depression, anxiety about interacting with other people, and isolation. Two-thirds of patients said they did not know anyone else who had been diagnosed with SD, and even after diagnosis, less than half of patients still said they did not know anyone else with SD. Nearly all patients and HCPs agreed that it was challenging to hide SD symptoms, and most patients felt embarrassed when people commented on their SD symptoms. Most patients agreed that they would be further along in their career if they did not have SD, and SD symptoms made them less confident at work and less likely to want to interact with people at work. Almost half of patients reported ever missing work as a result of SD symptoms.

CONCLUSION

These insights emphasize the physical and emotional patient burden associated with SD, impacting all aspects of patients' lives. Graphical abstract available for this article.

Association of air pollution with incidence of late-onset seborrhoeic dermatitis: a prospective cohort study in UK Biobank

BACKGROUND

Late-onset seborrhoeic dermatitis seriously affects patients' quality of life. Studies have shown an association between air pollution and other inflammatory skin diseases. However, associations between air pollution exposures and the incidence of late-onset seborrhoeic dermatitis have not been elucidated.

OBJECTIVES

To investigate air pollution's role in the incidence of late-onset seborrhoeic dermatitis.

METHODS

We engaged a prospective cohort analysis utilizing the UK Biobank database. Exposure data spanning various years for specific air pollutants, namely particulate matter [PM; with an aerodynamic diameter of ≤ 2.5 µm (PM2.5), between 2.5 and 10 μm (PM2.5-10), ≤ 10 μm (PM10)] along with nitrogen oxides (NO plus NO2, denoted NOx) and NO2, were incorporated. Through a composite air pollution score constructed from five pollutants and employing Cox proportional hazards models, the relationship between air pollution and seborrhoeic dermatitis was delineated.

RESULTS

Our examination of 193 995 participants identified 3363 cases of seborrhoeic dermatitis. Higher concentrations of specific pollutants, particularly in the upper quartile (Q4), were significantly linked to an elevated risk of seborrhoeic dermatitis. Notably, PM2.5, PM10, NO2 and NOx exhibited hazard ratios of 1.11, 1.15, 1.22 and 1.15, respectively. The correlation was further solidified with a positive association between air pollution score increments and onset of seborrhoeic dermatitis. Intriguingly, this association was accentuated in certain demographics, including younger men, socioeconomically deprived people, smokers, daily alcohol consumers, and those engaging in regular physical activity.

CONCLUSIONS

Our findings revealed that air pollution exposures were associated with incidence of late-onset seborrhoeic dermatitis. These results emphasize the importance of preventing environmental air pollution exposures to mitigate the risk of developing the condition.

Physical influences on the skin barrier and pathogenesis of allergy

PURPOSE OF REVIEW

As the incidence of allergic conditions has increased in recent decades, the effects of climate change have been implicated. There is also increased knowledge on the effects of other physical influences, such as scratching and Staphylococcus aureus . The skin barrier is the first line of defense to the external environment, so understanding the ways that these factors influence skin barrier dysfunction is important.

RECENT FINDINGS

Although the impact on environmental exposures has been well studied in asthma and other allergic disorders, there is now more literature on the effects of temperature, air pollution, and detergents on the skin barrier. Factors that cause skin barrier dysfunction include extreme temperatures, air pollution (including greenhouse gases and particulate matter), wildfire smoke, pollen, scratching, S. aureus, and detergents.

SUMMARY

Understanding the ways that external insults affect the skin barrier is important to further understand the mechanisms in order to inform the medical community on treatment and prevention measures for atopic conditions.

Associations between home environmental factors and childhood eczema and related symptoms in different cities in China

Previous studies have shown significant associations between home environmental factors and childhood eczema. However, few studies have compared how associations differ in different regions. This study investigated associations between home environmental factors and childhood eczema ever, and related symptoms including itchy rash (IR) and being awakened by itchy rash at night (awake by IR) in 4 cities located in different regions of China, based on cross-sectional investigations during 2010-2012. We used two-step analysis to explore the associations between influencing factors and eczema/related symptoms: first, group Least Absolute Shrinkage and Selection Operator (LASSO) was conducted to identify important factors among a list of candidates; then, the associations in total study population and in each city were estimated using logistic regression. We found these home environmental factors to be risk factors for eczema or related symptoms: large residence size, shared room, air cleaner at home, abnormal smell, perceived dry air, visible mold or damp stains, cooking with coal or wood, painted wall, incense, mice, new furniture during pregnancy, abnormal smell at birth, window condensation at birth and environmental tobacco smoke at birth. Environmental protective factors were rural house location and window ventilation. Associations of factors with eczema/related symptoms differed across cities. For example, air conditioning was protective for eczema in Beijing and awakening by IR in Shanghai with ORs of 0.70 (95%CI: 0.52, 0.95) and 0.33 (95%CI: 0.14, 0.81) respectively, but not significant in other cities. Our results have implications for improving home environments to reduce the risk of childhood eczema/related symptoms in different regions of China.

Effects of climate and environment on migratory old people with allergic diseases in China: Protocol for a Sanya cohort study

Background

Several studies have reported that the mountain climate can alleviate asthma, however, the effect of tropical climate on migratory elderly, especially in people with respiratory or allergic diseases is unknown.

Objectives

This cohort study aims to explore impact of climate and environmental changes on allergic diseases in migratory old people.

Methods

In this prospective cohort study, we recruited 750 older migratory people, the majority of whom were homeowners to minimize the risk of loss to follow up. The study's inclusion criteria were elderly individuals had moved from northern China to Sanya and suffered from either asthma or allergic diseases. Prior to participation, these individuals provided informed consent and underwent baseline assessment. Subsequently, they will be followed for three years. A face-to-face interview was conducted to gather information regarding their living environment and habits. Trained investigators administered the questionnaires and performed physical examinations including height, weight, and blood pressure, while a professional respiratory doctor conducted pulmonary function tests. Blood samples were promptly tested routine blood test, liver function, kidney function, glucose, triglyceride, allergens, and inflammatory factors. Climate and environmental data were obtained from Sanya Meteorological Bureau and Ecological Environment Bureau, respectively. We primarily compared the differences of participants with asthma or allergic diseases between northern China and Sanya in southern China by Chi-square test, t-test or Wilcoxon rank-sum test.

Findings

A total of 750 participants were recruited in this cohort from fourteen communities. All participants were surveyed questionnaires about health and family environment, underwent physical examinations, and collected biological samples for laboratory examinations.

Novelty

This is the first study to evaluate the effects of tropical climate and environment on elderly migrants from cold regions. This study has important implication for the health tourism and aging health, especially for the elderly migrants who suffered the respiratory and allergic diseases. Furthermore, this cohort study establishes a solid foundation for investigating the influence of environmental changes on elderly migrants with allergic diseases.

Establishment of clinical evaluation criteria for scalp seborrheic dermatitis

PURPOSE

To evaluate the three symptom indicators of scalp seborrheic dermatitis (SSD), namely scalp flaking, maximum erythema area, and pruritus, to develop a "16-point scale," to explore its relationship with the severity of SSD, and verify the reliability of the 16-point scale.

METHOD

A dermatologist evaluated patients with SSD using a 16-point scale, and statistically analyzed the collected data with the help of SPSS 26.0 software. The measurement data are expressed as (mean ± SD), and the intergroup comparison was done using a non-parametric test. We performed the correlation analysis using the bivariate correlation analysis method, and the relationship among non-normal distribution data variables were analyzed using Spearman's correlation coefficient. p < 0.05 indicated that the difference was statistically significant.

RESULTS

The total score of the "16-point scale" strongly correlated with the severity of disease, where scalp flaking had the strongest correlation. As compared with a single score, the correlation of the total score with the severity of disease was higher. The scoring range for mild patients was (0, 5], that for moderate patients was (5, 9], and that for severe patients was (9, 16].

CONCLUSION

A "16-point scale", consisting of items for adherent scalp flaking (0-10), maximum erythema area (0-3), and pruritus (0-3), was used to score the patients with SSD, and the total score was strongly correlated with and differentiated the severity of SSD. Recommended evaluation criteria: a total score of 0-5 points indicates mild SSD, 6-9 points indicates moderate SSD, 10-16 points indicates severe SSD. These criteria can help to standardize disease diagnosis and treatment, and efficacy assessment.

Impact of Air Pollution on Atopic Dermatitis: A Comprehensive Review

Air pollution is associated with multiple health problems worldwide, contributing to increased morbidity and mortality. Atopic dermatitis (AD) is a common allergic disease, and increasing evidence has revealed a role of air pollution in the development of atopic dermatitis. Air pollutants are derived from several sources, including harmful gases such as nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO), as well as particulate matter (PM) of various sizes, and bioaerosols. Possible mechanisms linking air pollution to atopic dermatitis include damage to the skin barrier through oxidative stress, increased water loss, physicochemical injury, and an effect on skin microflora. Furthermore, oxidative stress triggers immune dysregulation, leading to enhanced sensitization to allergens. There have been multiple studies focusing on the association between various types of air pollutants and atopic dermatitis. Since there are many confounders in the current research, such as climate, synergistic effects of mixed pollutants, and diversity of study population, it is not surprising that inconsistencies exist between different studies regarding AD and air pollution. Still, it is generally accepted that air pollution is a risk factor for AD. Future studies should focus on how air pollution leads to AD as well as effective intervention measures.

The Expression of Plasmacytoid Dendritic Cells and TLR7/9-MyD88-IRAKs Pathway in Chronic Eczema Lesions

Purpose

To investigate the expression of Plasmacytoid Dendritic Cells (pDCs) and TLR7/9-MyD88-IRAKs pathway in chronic eczema lesions.

Patients and Methods

Lesional tissues and the surrounding healthy tissues were collected from 25 individuals with chronic eczema, and immunohistochemistry was used to detect and comparatively analyze the expression profile of CD123, CD2AP, toll-like receptor 7 (TLR7), toll-like receptor 9 (TLR9) along with interleukin-1 receptor-associated kinase 1 (IRAK1) and interferon regulatory factor 7 (IRF7) in signaling pathways.

Results

The positive rates of CD2AP + pDC and CD123 + pDC in lesional tissues were significantly elevated compared to the surrounding healthy tissues (P < 0.05). They were distributed in both the epidermal and dermal layers of the lesional tissue, but the majority were in the dermal layer. The TLR7, TLR9, IRAK1 and IRF7 were more expressed in dermal layers of the lesional tissue with higher positive rates of expression compared to the surrounding healthy tissues (P < 0.05). IRAK1 and IRF7 were expressed in a small amount in the epidermal layer with higher positive rates of expression than in the surrounding healthy tissues (P < 0.05), while the positive rates of TLR7 and TLR9 expression in the epidermal layer were not statistically different from those in the surrounding healthy tissues (P > 0.05).

Conclusion

PDC and TLR7/9-MyD88-IRAKs pathways are actively expressed in chronic eczema lesions and may be involved in pathogenesis and disease progression.

Short-term effect of ambient temperature and ambient temperature changes on the risk of warts outpatient visits in Hefei, China: a retrospective time-series study

Concerns are growing about the adverse health effects of ambient temperature and ambient temperature changes. However, the association between ambient temperature and ambient temperature changes on the risk of warts outpatient visits is poorly understood. Our study used the distributed lag non-linear model (DLNM) aimed to evaluate the association between ambient temperature, ambient temperature changes (including temperature change between neighboring days (TCN) and diurnal temperature range (DTR)), and warts outpatient visits. We also performed subgroup analyses in order to find susceptible populations by gender and age groups. The maximum relative risk (RR) of low ambient temperature (0 °C) for warts outpatient visits was 1.117 (95% CI: 1.041-1.198, lag 04 days), and the maximum RR of high ambient temperature (32 °C) for warts outpatient visits was 1.318 (95% CI: 1.083-1.605, lag 07 days). The large temperature drop (TCN =  - 3 °C) decreased the risk of warts visits, with the lowest RR value at the cumulative exposure of lag 7 days (RR = 0.888, 95% CI: 0.822-0.959), and the large temperature rise (TCN = 2 °C) increased the risk of warts visits, with the highest RR value at the cumulative exposure of lag 7 days (RR = 1.080, 95% CI: 1.022-1.142). Overall, both low and high ambient temperatures and large temperature rise can increase the risk of warts visits, while large temperature drop is a protective factor for warts visits. However, we did not find any association between DTR and warts visits. Furthermore, subgroup analyses showed that males and the young (0-17 years old) were more sensitive to low and high ambient temperatures, and the elderly (≥ 65 years old) were more susceptible to TCN. The results may provide valuable evidence for reducing the disease burden of warts in the future.

Air Pollution and Atopic Dermatitis, from Molecular Mechanisms to Population-Level Evidence: A Review

Atopic dermatitis (AD) has increased in prevalence to become the most common inflammatory skin condition globally, and geographic variation and migration studies suggest an important role for environmental triggers. Air pollution, especially due to industrialization and wildfires, may contribute to the development and exacerbation of AD. We provide a comprehensive, multidisciplinary review of existing molecular and epidemiologic studies on the associations of air pollutants and AD symptoms, prevalence, incidence, severity, and clinic visits. Cell and animal studies demonstrated that air pollutants contribute to AD symptoms and disease by activating the aryl hydrocarbon receptor pathway, promoting oxidative stress, initiating a proinflammatory response, and disrupting the skin barrier function. Epidemiologic studies overall report that air pollution is associated with AD among both children and adults, though the results are not consistent among cross-sectional studies. Studies on healthcare use for AD found positive correlations between medical visits for AD and air pollutants. As the air quality worsens in many areas globally, it is important to recognize how this can increase the risk for AD, to be aware of the increased demand for AD-related medical care, and to understand how to counsel patients regarding their skin health. Further research is needed to develop treatments that prevent or mitigate air pollution-related AD symptoms.

Heat and outpatient visits of skin diseases – A multisite analysis in China, 2014–2018

Background

Many studies have shown that various kinds of diseases were associated with the variation of ambient temperature. However, there’s only a scrap of evidence paying attention to the link between temperature and skin diseases, and no relevant national research was performed in China.

Objective

This study aimed to quantify the effect of heat on skin diseases and identify the vulnerable populations and areas in China.

Methods

Daily meteorological data, air pollutant data and outpatient data were collected from in 18 sites of China during 2014–2018. A time-series study with distributed lag nonlinear model and multivariate meta-analysis was applied to analyze the site-specific and pooled associations between daily mean temperature and daily outpatient visits of skin diseases by using the data of warm season (from June to September). Stratified analysis by age, sex and climate zones and subtypes of skin diseases were also conducted.

Results

We found a positive linear relationship between the ambient temperature and risk of skin diseases, with a 1.25% (95%CI: 0.34%, 2.16%) increase of risk of outpatient visits for each 1 °C increase in daily mean temperature during the warm season. In general, groups aged 18–44 years, males and people living in temperate climate regions were more susceptible to high temperature. Immune dysfunction including dermatitis and eczema were heat-sensitive skin diseases.

Conclusions

Our findings suggested that people should take notice of heat-related skin diseases and also provided some references about related health burden for strategy-makers. Targeted measures for vulnerable populations need to be taken to reduce disease burden, including monitoring and early warning systems, and sun-protection measures.