Prevalence, Different Factors Associated with Atopic Dermatitis Identified in Study

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Individuals with active atopic dermatitis are shown to have significantly more visits to dermatologists and general practitioners than those with inactive disease, new findings suggest, as well as more dermatological drug deliveries and greater use of topical corticosteroids and phototherapy.¹

In addition, these data point to the estimated prevalence of atopic dermatitis among adults in the French population being nearly double prior estimates. This research was authored in part by Khaled Ezzedine, from the department of dermatology at the Henri Mondor Hospital - Paris-Est Créteil University in France.

Atopic dermatitis’s prevalence is known to have been increasing over the past 20 years, with infants being mostly affected but with disease also persisting into adulthood. Therefore, Ezzedine and colleagues sought to explore more about the disease within the French population.

“The main objective of the PreDDA study was to estimate adult prevalence of [atopic dermatitis] in a French representative population-based cohort of adults (CONSTANCES), and to describe factors associated with different profiles of [atopic dermatitis],” Ezzedine and colleagues wrote.^1,2

Analyzing Prevalence of Atopic Dermatitis and Associated Factors

The investigative team found that there had been 99,103 individuals who responded to their 2018 questionnaire, or 62.4% of their initial 158,898 participants. The team highlighted that 10,950 of these 99,103 individuals reported having experienced atopic dermatitis at some point in their lives and were, consequently, included in their research.

The investigators sent a follow-up questionnaire in 2022 to these individuals to obtain more information about their disease characteristics and about its impact on their quality of life. They found that 84.3% of the 6,132 subjects confirmed their diagnosis of the skin condition (AD+), adding that the majority reported that their diagnosis had been made by a dermatologist (38.7%) or a general practitioner (31.8%), and only 5.9% were shown to have been self-diagnosed.

The investigators asked about current disease status, highlighting that 49.0% of respondents noted that their atopic dermatitis was inactive (ADi). They added that 45.6% noted that had been regularly experiencing active symptoms (ADa). The team found that among subjects with active disease, levels of severity were categorized as mild for 43.4%, moderate for 41.6%, or severe (15.0%). The most frequently impacted areas were noted as hands and fingers for 42.0%, and the scalp for 36.0%.

The investigative team looked at quality of life (QoL) among patients using using the Dermatology Life Quality Index (DLQI). They concluded that only 5.0% of the respondents with active atopic dermatitis had no impact on their daily life. Such a percentage was noted by the team as lower than the 23.3% which had been observed in a prior French study.

Using the Atopic Dermatitis Control Tool (ADCT), the research team found that 43.6% of those labeled as ADa in the PreDDA analysis had uncontrolled disease, compared to 71.4% of those in the prior study. They highlighted that overall prevalence of the inflammatory disease in the French adult population was estimated at 9.1%–9.5%.

Notably, the prevalence estimate was shown to be approximately double the previously reported 4.7% figure. In additional breakdowns of prevalence data, the team concluded that 2.1%–2.6% of cases involved atopic dermatitis that began during the patient's adulthood, 2.5%–2.9% had disease that began before adulthood and persisted into later years, and 3.1%–3.5% noted having childhood-onset disease that did not continue.

The investigators also matched participants who responded to the 2022 survey by age and sex in a 1:1 ratio, using a 6,132-person control group who had no reported history of the disease in Q2018 (AD−). Compared to both AD− and ADi individuals, it was found that patients showing active atopic dermatitis were more likely to have higher levels of education (P < .001) and a higher socioeconomic status (P = .002).

Both those in the ADa and ADi groups were shown to have a significantly higher prevalence of neuropsychological and neuropsychiatric disorders (P < .001 for both), pulmonary conditions (P < .001), sleep disorders (P = .043), metabolic disorders (P = .043), other dermatological conditions (P < 0.001), and liver diseases (P = .025).

After the investigators linked healthcare resource utilization data from the period between 2019 - 2021 to the national medico-administrative database (SNDS), they found that those showing active disease had significantly higher rates of general practitioner interactions (P < .001) and dermatologist interactions (P < .001) versus those in the AD− or ADi cohorts.

Those with active atopic dermatitis also received more prescriptions for dermatological medications (P < .001), including topical corticosteroids (P < .001). The team added that these subjects were also more likely to be given phototherapy (P = .009).

“This study provided an initial overview of [atopic dermatitis] in France, with a significant degree of precision and detail,” they wrote. “The main limitation is that the confirmation of the diagnosis was not collected directly from the physician. Nevertheless, PreDDA could be used to perform additional analyses to better understand the characteristics associated with certain sub-populations of interest.”¹

References

1. Ezzedine, K., Hourblin, V., Connétable, S., Ruiz, F., Ziad, A., Sobczak, A., Kab, S., Renuy, A., Goldberg, M., Zins, M. and Nosbaum, A. (2025), Atopic dermatitis in the French cohort CONSTANCES (PreDDA study): Focus on persistence and remission in adulthood. J Eur Acad Dermatol Venereol. https://doi.org/10.1111/jdv.20595.

2. Zins M, Goldberg M, CONSTANCES team. The French CONSTANCES population-based cohort: design, inclusion and follow-up. Eur J Epidemiol. 2015; 30(12): 1317–1328.