April 2025 digest

Research Trends in Epidemiology and Genetics of Atopic Dermatitis

The Rise of Atopic Dermatitis in the Elderly Population

Until the early 2000s, atopic dermatitis (AD) was primarily considered a pediatric condition. In older adults, a diagnosis of AD was often dismissed due to its perceived low incidence and frequently misclassified as senile pruritus, pre-bullous pemphigoid, or cutaneous T-cell lymphoma (CTCL) often without sufficient clinical justification.­

As of 2025, with the global population aging rapidly, AD in older adults is becoming an increasingly important public health concern. A recent global study examined the prevalence of AD in individuals over 60 and projected trends through 2050 (DOI: 10.3389/fpubh.2025.1569119). Between 1990 and 2021, the number of older adults affected by AD rose substantially—now surpassing 11 million people worldwide. This growth is largely due to population aging and growth, rather than an increase in the age-adjusted rate of the disease. Notably, women and individuals aged 75–79 showed the highest incidence rates. AD is also more prevalent in high-income countries with higher Socio-Demographic Index (SDI) scores. However, disparities between countries have slightly decreased over time.­

Looking ahead to 2050, the total number of older adults with AD is expected to continue increasing, even though age-standardized rates may decline slightly. This indicates that, despite stable or falling individual risk in some regions, the overall burden of AD among the elderly will continue to grow—underscoring the urgent need for age-specific treatment strategies, preventive care, and tailored public health policies, particularly in aging societies.­

As highlighted by our Chinese colleagues, there is also a growing need to refine diagnostic criteria for AD in the elderly to avoid overlooking other serious conditions, such as CTCL. This may require a greater use of skin biopsies in older patients presenting with chronic pruritic dermatoses.

Genetic Insights into Allergic Multimorbidity

Allergic diseases—including asthma, AD, and hay fever—are common and frequently occur together in the same individuals. This progression is often referred to as the “atopic march,” where one allergic condition can lead to another. However, the genetic reasons behind this allergic multimorbidity are not yet fully understood. A novel approach called Genomic Structural Equation Modeling (Genomic-SEM) has been developed to study shared genetic factors across multiple diseases simultaneously, rather than examining each one in isolation. By combining different allergic traits with large-scale genetic data, researchers were able to identify 31 novel genetic variants and 31 genes linked to multiple allergic disorders (DOI: 10.1186/s12967-025-06465-8). ­

Some of these genes had not been previously associated with allergies. For example: RAVER2, which may affect how immune-related genes are spliced, UBDP1, involved in protein breakdown within the immune system, MED24, a regulator of gene expression in immune cells,and SOX5, which plays a role in T-cell regulation, a key component in allergic responses. ­

Many of the identified allergic multimorbidity genes are involved in immune system signaling, particularly T-cell activity and inflammation. Intriguingly, several of these genes are also associated with neuropsychiatric conditions such as ADHD and bipolar disorder, as well as with glioma, suggesting a complex network of genetic interactions that may link immune and neurological pathways.

RECORDING & PRESENTATIONS AVAILABLE

RAJKA 2025 Important dates

GET READY!

• Call for Abstract opens from May 5th to mid-July (notification of acceptance in late August)
• Registration system starts mid May
• Meeting from October 24 to 26, 2025

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