Global trends and modifiable risk factors for atopic dermatitis incidence: Insights from GBD 2021

Abstract

Background: Global patterns in atopic dermatitis (AD) incidence and their associations with modifiable risk factors remain unclear.

Objective: We sought to analyze global trends in AD incidence and identify associated socioeconomic, environmental, and lifestyle factors contributing to its global disparities and epidemics.

Methods: Data on AD in 204 countries and territories from 1990 to 2021 were extracted from the Global Burden of Diseases Study 2021. Age-standardized incidence rates (ASIRs) were calculated by sex and region. Socioeconomic development was measured by the Sociodemographic Index, a composite indicator of income, education, and fertility. Modifiable risk factors-including high body mass index, low physical activity, air pollution, and unhealthy diets-were quantified using summary exposure values, reflecting the population-level exposure to each risk. Dietary risks included diet high in sugar-sweetened beverages, processed meat, and sodium, and low intake of whole grains. Relationships between ASIRs and summary exposure values were independently assessed using restricted cubic spline regression.

Results: In 2021, 16.0 million new cases of AD were recorded globally, with the highest ASIRs in high-income Asia Pacific (474.8 per 100,000 population) and Western Europe (421.7 per 100,000 population) geographically and higher ASIRs in women. AD incidence strongly increased with socioeconomic development. Among modifiable risk factors, high body mass index, low physical activity, and nitrogen dioxide pollution formed positive associations with AD risk. Diets rich in sugar-sweetened beverages, processed meat, and sodium and diet low in whole grains further increased the risk.

Conclusions: Global disparities in AD incidence trends are closely linked to socioeconomic development and modifiable risk factors, including obesity, air pollution, and unhealthy diets. Addressing these factors through targeted public health policies is essential to mitigating the global burden of AD, particularly in industrialized and rapidly developing regions.

Keywords: Atopic dermatitis; Global Burden of Disease study; incidence; risk factors.

Fig 1

The global incidence of AD in 204 countries and territories. A, ASIR in 2021. B, EAPC in ASIR from 1990 to 2021.

Fig 2

The change in the incidence of AD across different age groups, sexes, and SDI regions from 1990 to 2021. A, Change in ASIR by SDI. B, EAPC of ASIR by SDI. C, Change in ASIR by sex. D, EAPC of ASIR by sex.

Fig 3

Association between the SDI, unhealthy lifestyle, and air pollution and the ASIR of AD at national level in 2021. A, SDI. B, SEV of high body mass index. C, SEV of low physical activity. D, SEV of ambient particulate matter pollution. E, SEV of ambient ozone pollution. F, SEV of nitrogen dioxide pollution. G, SEV of diet low in whole grains. H, SEV of diet high in sugar-sweetened beverages. I, SEV of diet high in sodium. J, SEV of diet high in processed meat. K, SEV of diet high in red meat. L, SEV of diet low in milk.

Fig 4

Association between the SEV of high body mass index and the ASIR of AD at national level in 2021. A, High-SDI countries. B, Low- to middle-SDI countries.