Study Highlights Trends in Atopic Dermatitis Web Search Volume in Europe

Atopic dermatitis (AD) web search volume saw an increase between 2019 - 2023 in 21 European countries, according to recent findings, with correlations observed between web search volume and climates with humid, cold, and windy weather.¹

These findings and more were the results of new research conducted to evaluate atopic dermatitis-related searches on the Internet across various European countries, with the overall goal being an assessment of spatiotemporal variations and links between external and disease-related factors.

This new research was led by Hannah Wecker, from the department of dermatology and allergy at Technical University’s TUM School of Medicine and in Munich, Germany. Wecker et al. noted that crowdsourced web data regarding atopic dermatitis has been identified previously in single countries as well as globally, though the latter was to evaluate the popularity of search terms.²

“The aim of the study was to investigate (atopic dermatitis)-related web searches in 21 different European countries to identify possible regional and seasonal variations, as well as associations between web searches and disease-related and external factors such as socioeconomic and meteorological data,” Wecker and colleagues wrote.

Background and Methods

The investigators implemented a retrospective longitudinal study design in which they utilized Google Ads Keyword Planner for the purposes of gathering Internet search data that related to eczema or atopic dermatitis across 21 different countries in Europe.

These included Bosnia and Herzegovina, Croatia, Austria, Ireland, Czechia, Denmark, Sweden, Germany, France, Hungary, Greece, Italy, Malta, Portugal, Netherlands, UK, Poland, Serbia, Romania, Ukraine, and Spain. The Planner had originally been used for marketing but has since become a commonly-used tool for medical research.

The research team entered specific terms for their searches such as “atopic dermatitis” and “atopic eczema,” in addition to the terms’ lay equivalents. They did this using the respective native languages of each country, seeking to capture the wide variety of Internet searches and contribute to the ongoing dialogue regarding the most useful terminology for atopic dermatitis.

The team implemented professional translators and AI-based tools as needed with the goal of maintaining accurate translations across the various languages used in searches. Their country selection had been based upon expert input and the goal was to allow for comprehensive representation.

Data were gathered by the investigators such as keywords as well as monthly search volumes, and these were all assessed in the period between February 2019 - January 2023, with the research team normalizing the data per 100,000 inhabitants for their comparative analysis. They also explored spatiotemporal patterns and associations that could be identified between trends in searches as well as different factors related to socioeconomic indicators, prevalence of disease, and meteorological conditions.

Findings

More than 241 million web searches were evaluated by the research team regarding atopic dermatitis statistics, demonstrating substantial variation as far as search volume across the various European countries (P < .001). The observed variation noted by the team was also shown to correlate with atopic dermatitis prevalence as well as burden of disease (both r = .51, P = .019).

The investigators reported there had been an increase in web search volume in the timeframe between 2019 - 2023 across all countries, noting that peaks typically took place in January and in March. Furthermore, the team found that there had been negative correlations between volume and median age of population (r = −.46, P = .039), in addition to the number of general practitioners (r = −.29, P = .226) and number of specialists (r = −.27, P = .270).

The research team also highlighted factors related to weather as playing a role, expressing that moderate to strong correlations were observed between volume and humid, cold, and windy climate conditions with fewer hours of sunlight. The team added that, typically, higher online interest would follow 1–3 months after these weather patterns.

“Using crowdsourced data offers versatile opportunities to gain further insights into this complex dermatological condition, such as monitoring search behavior for developments due to climate change or uncovering unmet needs in the population,” they wrote. “The seasonal trend in web searches for AD coincides with the seasonal exacerbation of AD during cold and humid weather, emphasizing the necessity for intensified public health campaigns…and adjustment of treatment plans during these periods.”

References

1. ^{Wecker H, Ziehfreund S, Sitaru S, Johansson EK, Elberling J, Doll A, et al. Burden of atopic dermatitis in Europe: A population-centred approach leveraging web search data in 21 European countries. J Eur Acad Dermatol Venereol. 2024; 00: 1–12. https://doi.org/10.1111/jdv.19989.}
2. ^{Xu S, Thyssen JP, Paller AS, Silverberg JI. Eczema, atopic dermatitis, or atopic eczema: analysis of global search engine trends. Dermatitis. 2017; 28(4): 276–279.}