Sustained Rise Observed in Atopic Dermatitis Cases, Prevalence Rates in Older US Adults

There has been an overall increase in atopic dermatitis prevalence among the oldest-old adults within the US, new findings suggest, with increases in atopic dermatitis cases among older adults by 85.53% from 1990 - 2019.1

These findings further suggested mixed gender-related disparities among such patients, with higher age-specific rates of prevalence among males and cases among females. Minmin Wang—from the Department of Global Health at the Peking University School of Public Health in Beijing—led the team of investigators in the analysis that led to these results.

“In the present study, we aimed to evaluate the sex disparities in prevalence and influencing factors among the US oldest-old adults,” Wang and colleagues wrote.1 “Our findings may provide valuable insights for the management of elderly [atopic dermatitis] among this population.”

The study’s investigators looked at older adult patients aged 80-84, 85-89, 90-94, and 95 years and older. They assessed US-based prevalence data on atopic dermatitis in the period from 1990 - 2019, with the necessary data being collected from the Global Burden of Disease (GBD) 2019 study.2

The team assessed rates of atopic dermatitis prevalence as well as the number of disease cases, exploring the epidemiological profile of atopic dermatitis among this older population of subjects. They also projected future trends from 2020 - 2030 through the use of a Bayesian age-period-cohort model.

The analysis examined trends over time by various factors such as calculated male-to-female case ratios, sex, and used age-period-cohort modeling stratified by sex to isolate the impacts on the results of timeframe, age, and birth cohort on shifts in the disease's prevalence. Quantification of the roles of population growth, aging, and prevalence rate shifts in driving the rise in atopic dermatitis cases was done using Das Gupta's decomposition method.

The investigators concluded that between 1990 - 2019, the number of disease cases in this age cohort rose by 85.53%, with a larger absolute and relative increase being identified by the study among males—126.09% compared to 63.39% in females. The investigative team noted that the forecasts suggest continuation of this upward trend, with approximately 467,700 cases being likely by 2030.

In all of the evaluated age brackets, women were shown to have made up the majority of cases, with the team highlighting male-to-female case ratios ranging from 0.40 - 0.85. This pattern was highlighted by the research team as a “high-female case disparity," although there has been a gradual reduction in the sex gap since 1990.

The age-standardized prevalence rate (ASPR) for atopic dermatitis as of 2019 in this elderly cohort was noted by the team as 2,471.79 per 100,000 patients. From 1990 - 2019, an increase in ASPR at an average annual rate of 0.14% took place, with males reporting a slightly quicker rise (0.13% per year) versus the 0.08% per year rise among females.

Men were noted by the investigators as showing consistently higher rates of disease prevalence across all 4 of the previously highlighted age groups, with male-to-female prevalence rate ratios showing a range from 1.10 - 1.45. This was referred to in the study as a “high-male rate disparity," and it was more pronounced in the older age groups.

The investigative team expressed that the age effect component of their modeling confirmed higher age-specific prevalence rates seen among males, which they noted aligns with the observed “high-male rate disparity.” Comparable patterns were shown in both sexes by period and cohort effects. Population rises were pointed to as the predominant factor impacting the rising number of cases.

Overall, the study found a sustained rise in both the number of atopic dermatitis cases and prevalence rates among the oldest-old adults in the US, as well as suggesting a dual pattern of sex disparity. Nevertheless, the team highlighted their research's potential limitations in their conclusion.

“This study had several limitations,” they wrote.1 “Detailed information on [atopic dermatitis] was not available in the GBD database, such as data on risk factors, which prevented further analyses. Additionally, we do not have access to prevalence data of [atopic dermatitis] by states, and we are unable to analyse the regional distribution of prevalence.”

References

1. Wang, M., Cao, X., Zhou, M., Mi, Y., Yu, P. and Guo, Y. (2025), Mixed Sex Disparities in Elderly Atopic Dermatitis Prevalence Among US Oldest-Old Adults: A Longitudinal Study. Clin Exp Allergy. https://doi.org/10.1111/cea.70060.

2. Global Burden of 369 Diseases and Injuries in 204 Countries and Territories, 1990–2019: A Systematic Analysis for the Global Burden of Disease Study 2019,” Lancet 396, no. 10258 (2020): 1204–1222, https://doi.org/10.1016/s0140-6736(20)30925-9.