New Childhood Eczema Research

Researchers from the Icahn School of Medicine at Mount Sinai, Weill Cornell Medicine and other institutions say they have uncovered a key biological explanationwhy eczema so often starts in childhood. The study, conducted on young mice, found that some types of immune cells in early-life skin are more reactive than those in adults. This difference may help explain why children are more vulnerable to inflammation and allergic skin disease, according to the study authors.   

The findings were published in the Feb. 25 online issue of Nature.

“We found that allergy risk is shaped very early in life, when the skin’s immune system is biologically programmed to overreact to allergens, with important consequences for understanding how immune-mediated diseases emerge and should be treated,” says senior study author Shruti Naik, PhD, associate professor of immunology and immunotherapy and dermatology at the Icahn School of Medicine. “By pinpointing the cells and hormonal signals that control this window of vulnerability, we open the door to strategies that could prevent allergic disease before it spreads from the skin to the lungs, gut, and beyond.”

Dendritic Cells

The researchers discovered that the dendritic cell in young skin behaves differently than in adults, responding faster and more strongly to allergens. This sets the stage for inflammation and eczema early in life. In adult skin, the same cells are far less reactive, according to the researchers.

The team also says it found that infants lack normal levels of stress hormones that later help keep immune reactions in check, allowing these allergic responses to take hold. Importantly, signs of the same immune activity were found in skin samples from children with early-onset eczema, but not in adults, suggesting this early-life window may also be important in humans, according to information shared by the Icahn School of Medicine.

“This work was only possible through a true clinic-to-lab collaboration—where insights from pediatric patients shaped the questions we asked in the lab,” noted study co-author Emma Guttman-Yassky, MD, PhD, the Waldman Professor of Dermatology and Immunology and Health System Chair of the Kimberly and Eric J. Waldman Department of Dermatology at the Icahn School of Medicine. “By studying allergic disease where it actually begins, in early life and by modeling clinically relevant allergens and disease features, lead author Yue Xing, PhD, uncovered immune biology that simply doesn’t appear in adult models. By revealing what’s unique about the early-life immune system, this work explains why eczema so often begins in infancy.”