Children with obesity more likely to develop immune-related skin conditions

New research highlights the significant link between childhood obesity and the increased likelihood of developing immune-mediated skin diseases (IMSDs), including conditions such as alopecia areata, atopic dermatitis, and psoriasis. The study underscores the importance of maintaining a healthy weight in childhood as a potential preventative measure against these skin conditions.

The findings, published in the Journal of Investigative Dermatology, are based on an extensive analysis of 2,161,900 Korean children tracked from 2009 to 2020. The study aimed to explore the relationship between obesity, dynamic changes in body weight, and the development of IMSDs over time.

IMSDs can have profound impacts on the quality of life, affecting children’s emotional, physical, social, and functional well-being, as well as that of their families. Although some biologics have shown promise in treating conditions like atopic dermatitis and psoriasis in children, there remains a dearth of effective treatment options. Furthermore, the lack of clinical trials for systemic therapies continues to pose significant challenges in managing IMSDs in paediatric populations.

In recent years, childhood obesity rates have risen sharply, exacerbating what has now become a pressing public health issue. The COVID-19 pandemic and associated lockdowns have further compounded this crisis. Despite the clear association between obesity and chronic inflammatory skin diseases, such as psoriasis and atopic dermatitis, the exact mechanisms through which obesity contributes to these conditions remain unclear.

Dr Seong Rae Kim, MD, Co-lead investigator of the study from the Department of Dermatology at Seoul National University College of Medicine, Seoul, Republic of Korea, explained, “Previously, many studies have looked at the link between childhood obesity and IMSDs. However, most of these studies only looked at data from one point in time or compared groups with and without the condition (i.e., obesity or overweight), and they had small sample sizes. Very few studies have followed children over a long period to see how their body weight affects the development of these skin conditions. This means we still don’t know for sure whether having obesity or overweight causes atopic dermatitis and psoriasis or if the opposite is true. Also, no studies have yet looked at the effect of body weight on alopecia areata or how dynamic changes in a child’s weight affect development of common IMSDs.”

The study stands out due to its scale and comprehensive approach, following children longitudinally to assess how fluctuations in body weight influence the risk of developing IMSDs. This extensive dataset, drawn from a national database covering nearly all infants and children in Korea, provided researchers with a unique opportunity to gain insights into the complex relationship between weight and skin health.

Dr Hyunsun Park, MD, Ph.D., another co-lead investigator from the same institution and a member of the Laboratory of Intestinal Mucosa and Skin Immunology, elaborated on the team’s broader research interests, stating, “Our research team is very interested in the skin-gut axis. We think that various factors, including diet, obesity, or other lifestyles can affect the gut environment and contribute to the development of IMSDs. We are trying to find the puzzle pieces to demonstrate how they are connected, and our current research is a step towards that understanding. We conducted a large study using data from a national database in Korea, which includes information on almost all infants and children across the country. Our goal was to see how a child’s weight and changes in their weight are related to the development of alopecia areata, atopic dermatitis, and psoriasis.”

The study’s results were telling. It was found that children with obesity had a higher likelihood of developing IMSDs compared to their peers of normal weight. Atopic dermatitis, in particular, showed the most significant association with changes in body weight. Children who transitioned from a normal weight to being overweight were at an elevated risk of developing atopic dermatitis. Conversely, those who managed to reduce their weight from overweight to normal had a reduced risk of developing the condition compared to children who remained overweight.

Dr Seong-Joon Koh, MD, Ph.D., another co-lead investigator from the Department of Internal Medicine and Liver Research Institute at Seoul National University College of Medicine, as well as the Laboratory of Intestinal Mucosa and Skin Immunology, concluded, “Our findings support the importance of promoting weight maintenance among children who are already within the normal weight range because it may help reduce the risk of developing atopic dermatitis. In addition, prevention of excessive weight gain and purposeful weight loss, including adopting healthy diet strategies in children with obesity to prevent atopic dermatitis, particularly before school age, should be promoted. Implementing purposeful interventions, including nutritional strategies, to decrease body weight may aid in reducing the risk of developing IMSDs in children.”

This study offers crucial insights that could influence public health strategies and clinical practices, advocating for early interventions in managing childhood obesity as a means to reduce the burden of IMSDs. The research underscores the need for continued exploration into the connections between body weight, lifestyle factors, and immune-mediated skin diseases to better understand how to prevent and treat these conditions effectively.