Research Reveals Why Eczema Often Starts in Childhood

Study finds immune cells in young skin are more reactive, explaining vulnerability to allergic inflammation

Published on Feb. 26, 2026

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A team of researchers has uncovered a key biological explanation for why eczema so often starts in childhood. The study, in young mice, found that some types of immune cells in early-life skin are more reactive than those in adults, a difference that may help explain why children are more vulnerable to inflammation and allergic skin disease. The findings suggest that early childhood represents a critical window for immune-driven skin disease and may shed light on why eczema is often the first condition in a broader pattern of allergic disease.

Why it matters

Eczema affects nearly one in four children and often appears early in life. It can also precede other allergic conditions, including asthma and food allergies. Until now, scientists have not fully understood why the disease is so strongly linked to early childhood. This research provides important insights into the biological mechanisms behind this phenomenon, which could lead to new strategies for preventing allergic disease before it spreads from the skin to other organs.

The details

The researchers discovered that a specific immune cell type, the dendritic cell, in young skin behaves differently than in adults. These cells respond faster and more strongly to allergens in young skin, setting the stage for inflammation and eczema early in life. In adult skin, the same cells are far less reactive. The team also found that infants lack normal levels of stress hormones that later help keep immune reactions in check, allowing these allergic responses to take hold.

  • The study was reported in the February 25, 2026 online issue of Nature.

The players

Shruti Naik

Associate Professor of Immunology and Immunotherapy, and Dermatology at the Icahn School of Medicine.

Emma Guttman-Yassky

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.

Yue Xing

Lead author of the study.

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What they’re saying

“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.”

— Shruti Naik, Associate Professor of Immunology and Immunotherapy, and Dermatology (Nature)

“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. 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.”

— Emma Guttman-Yassky, The Waldman Professor of Dermatology and Immunology (Nature)

What’s next

The investigators plan to explore ways to block this early-life immune pathway to stop allergic disease before it spreads from the skin to other organs.

The takeaway

This research provides important insights into the biological mechanisms behind why eczema so often starts in childhood, which could lead to new strategies for preventing allergic disease from developing in the first place. By understanding the unique features of the early-life immune system, researchers hope to find ways to intervene and stop these conditions before they become more widespread.