Study Highlights Advances in Understanding Risk, Prevention Measures for Atopic Dermatitis

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A new study suggests that dietary factors—such as intake of histamine-rich foods and sugar—may impact risk of atopic dermatitis as well as disease severity. Additionally, these findings suggest that allergens such as house dust mite allergens and aeroallergens may exacerbate disease symptoms.¹

These data resulted from a recent analysis led by Mo Xian, MD, from the department of pathology, microbiology and immunology at New York Medical College. Xian and colleagues noted that atopic dermatitis prevalence varies, with a stable plateau in Europe and North America but an increase in such countries as China.

The rise in prevalence was noted as higher in urban regions than in rural ones, with an international survey (AWARE 1) concluding that the top 3 countries or areas with the highest prevalence of the skin disease among adults were Thailand, mainland China, and Hong Kong.²

“These surveys highlight the high prevalence and morbidity among respondents, and show that (atopic dermatitis) is not just a childhood disease; there is disease persistence and chronicity in adults,” Xian et al. wrote. “In this review, we consider the impacts of the exposome at individual levels, including the influence of microorganisms, diet, pet keeping, obesity, and psychological factors, to identify potential intervention pathways.”¹

Data and Relevant Conclusions

The research team’s review emphasized that the concept of the "exposome" encompasses the totality of environmental exposures one experiences throughout a lifetime, beginning from conception. The exposome was noted as including both external influences, such as pollutants and environmental elements, and internal factors such as biological shifts.

This framework the team used was designed with the aim of exploring the complexities between such exposures and their impacts on patients' health. In the context of atopic dermatitis, interest in exposome research was also reported to be growing, particularly in understanding the roles of urban environments, climate change, air pollutants, social determinants, and race.

In this review, the investigators looked at the role of the skin microbiome in atopic dermatitis, noting that disruptions in the microbiome's balance can impair skin barrier function and trigger immune responses and nonspecific inflammation. Prior data showed that healthy skin is primarily colonized by bacteria from 4 major phyla: Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes.

However, the research team cited data on atopic dermatitis which demonstrated that such patients' microbiomes are less diverse, with notable shifts in both quantity and quality of microbial populations. As an example, they noted that Demodex folliculorum, a common ectoparasite, had been identified more commonly on patients with this inflammatory skin condition.

It had particularly been observed on lesional skin that had been treated with topical corticosteroids. Such an extoparasite was also shown by the team to be significantly more prevalent on non-lesional atopic dermatitis skin as opposed to the skin of healthy controls.

Similarly, the investigative team highlighted data showing that house dust mite allergens, especially Dermatophagoides pteronyssinus group 2, had been previously shown to be critical triggers among sensitized individuals. This would lead to exacerbated symptoms of atopic dermatitis through barrier disruption, skin inflammation, and rising keratinocyte activity.

The team also noted research that considered dietary influences on the presence of atopic dermatitis, specifically noting findings that had linked high sugar intake and fructose-rich beverage use with increased allergic sensitization.

Additionally, the investigators reported on prior data showing that histamine intolerance, resulting from reduced activity of the enzyme diamine oxidase (DAO), had been suggested as a potential factor in atopic dermatitis. They noted that lower-histamine diets were recommended to manage sensitivity symptoms.

The investigators' review also touched on the complex relationship between that prior research had found regarding body weight and atopic dermatitis. Specifically, these prior data had demonstrated a significant correlation between obesity and the inflammatory skin disease among both children and adults, despite mixed data on the role of birth weight.

In another area of focus, the team noted psychological factors, highlighting research indicating that stress and anxiety can lead to exacerbated itch symptoms among patients with atopic dermatitis. Furthermore, they noted that psychological interventions which are designed to target negative emotional states have been observed to be alleviating symptoms.

“Further understanding these environmental and exposome influences is crucial,” they wrote. “Research is still needed to elucidate specific mechanisms underlying these associations, especially the host–microbe–environment interactions, and to guide effective management approaches for this prevalent and burdensome skin disorder.”¹

References

1. ^{Xian, M., Maskey, A.R., Kopulos, D. and Li, X.-M. (2024), Advances of the exposome at individual levels and prevention in atopic dermatitis. Int J Dermatol. https://doi.org/10.1111/ijd.17559.}
2. ^{Maspero J, De Paula Motta Rubini N, Zhang J, Sanclemente G, Amador JR, El Sayed MH, et al. Epidemiology of adult patients with atopic dermatitis in AWARE 1: a second international survey. World Allergy Organ J. 2023; 16:100724.}