Surreal illustration of a baby surrounded by food particles, with a protective glowing aura around healthy skin.

The Age Factor: How Timing Affects Food Allergy Development in Babies

Elliot Brynn in Health & Wellness August 2025 • 4 min read.

"New Research Reveals the Optimal Age for Introducing Foods and Preventing Allergic Reactions in Infants"

Food allergies are on the rise, casting a shadow over family mealtimes and sparking concern among parents worldwide. As rates of food-related allergic reactions climb, researchers are racing to understand why some children develop these sensitivities while others don't. Recent studies suggest that early exposure to food proteins through damaged skin may play a significant role, highlighting the importance of a strong skin barrier in infants and young children.

A new study published in "Allergology International" sheds light on this critical period, identifying the optimal age for epicutaneous sensitization—the process by which allergens penetrate the skin and trigger an immune response. By understanding this age window, healthcare professionals and parents can work together to develop targeted strategies for preventing food allergies before they take hold.

This article delves into the groundbreaking findings of the study, explores the factors that influence food allergy development, and offers practical advice for parents navigating the complex world of infant feeding. Understanding this research can empower families to make informed decisions about their children's health and potentially reduce the risk of developing life-altering food allergies.

Decoding the Age Factor: The Mouse Model Revelation

Surreal illustration of a baby surrounded by food particles, with a protective glowing aura around healthy skin.

The researchers, led by Masato Tamari and his team, conducted a meticulous study using a mouse model to mimic the process of epicutaneous sensitization. They focused on BALB/c mice of varying ages—1, 3, 8, and 24 weeks old—exposing their tape-stripped skin to ovalbumin (OVA), a common allergen. This tape-stripping mimicked skin barrier damage, similar to eczema, which is known to increase the risk of food allergies.

The results revealed a striking age-dependent response. The 24-week-old mice exhibited the most pronounced allergic reactions, marked by a significant drop in body temperature after OVA challenge, elevated levels of OVA-specific IgE antibodies, and increased production of Th2 cytokines—immune molecules associated with allergic responses. Further investigation revealed that dendritic cells (DCs), key players in initiating immune responses, migrated more effectively to the draining lymph nodes in older mice, suggesting an enhanced ability to trigger allergic sensitization.

Key Findings:

Older mice (24 weeks) showed stronger allergic reactions.
Increased IgE antibody production in older mice.
Enhanced dendritic cell migration with age.
IL-33 plays a vital role in skin sensitization.

Importantly, the study also highlighted the role of interleukin-33 (IL-33), an inflammatory molecule released by skin cells. The researchers found that tape-stripping induced IL-33 expression in the skin, with levels increasing with age. This suggests that IL-33 may act as a critical trigger, amplifying the allergic response in older mice with compromised skin barriers. The study implies that the state of the skin and the resulting immune response are critically affected by age.

Implications for Parents and Future Research

While this study was conducted in mice, the findings offer valuable insights for understanding food allergy development in human infants. The research underscores the importance of maintaining a healthy skin barrier in babies, particularly those with eczema or a family history of allergies. Strategies such as regular moisturizing, gentle skincare practices, and prompt treatment of skin inflammation may help to reduce the risk of epicutaneous sensitization.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.alit.2018.01.003, Alternate LINK

Title: The Optimal Age For Epicutaneous Sensitization Following Tape-Stripping In Balb/C Mice

Subject: General Medicine

Journal: Allergology International

Publisher: Elsevier BV

Authors: Masato Tamari, Keisuke Orimo, Kenichiro Motomura, Ken Arae, Akio Matsuda, Susumu Nakae, Hirohisa Saito, Hideaki Morita, Kenji Matsumoto

Published: 2018-07-01

Everything You Need To Know

Why might the timing of introducing allergenic foods to babies be important in preventing food allergies?

Research indicates that the age at which babies are exposed to allergenic foods may significantly impact their likelihood of developing food allergies. The study using a mouse model, suggests that older mice (24 weeks) exposed to allergens through damaged skin exhibited more pronounced allergic reactions compared to younger mice. This highlights a critical period where the skin's barrier function and immune response may be more susceptible to sensitization. While this study focuses on a mouse model, the findings suggest the importance of understanding the timing of allergen introduction in infants. Further research is needed to fully understand the implications for human infants.

How did the researchers use tape-stripped skin and ovalbumin (OVA) in the mouse model to study food allergy development?

The study used BALB/c mice of varying ages (1, 3, 8, and 24 weeks old) to mimic epicutaneous sensitization. Researchers exposed tape-stripped skin to ovalbumin (OVA), a common allergen, to mimic skin barrier damage similar to eczema. This allowed them to observe the immune response in relation to age. The tape-stripping process induced IL-33 expression in the skin. This suggests that compromising the skin barrier increases the risk of allergic sensitization, and that this effect is age-dependent.

What were the key allergic responses observed in the older mice (24 weeks) in the epicutaneous sensitization study?

The study revealed that older mice (24 weeks) showed stronger allergic reactions, including a significant drop in body temperature after OVA challenge. These mice also exhibited increased IgE antibody production and enhanced dendritic cell migration to the draining lymph nodes. The study highlighted the role of interleukin-33 (IL-33) in skin sensitization, finding that IL-33 expression increased with age and amplified the allergic response in older mice with compromised skin barriers. It indicates that age plays a significant role in the development of allergic responses through the skin.

Based on this research, what practical steps can parents take to potentially reduce the risk of food allergies in their babies?

The findings underscore the importance of maintaining a healthy skin barrier in babies, particularly those with eczema or a family history of allergies. Regular moisturizing, gentle skincare practices, and prompt treatment of skin inflammation may help to reduce the risk of epicutaneous sensitization. The study highlights the connection between skin health, immune response, and early childhood sensitization. The research suggests that interventions aimed at protecting the skin barrier could potentially reduce the risk of developing food allergies.

What role do dendritic cells (DCs) and interleukin-33 (IL-33) play in the skin sensitization process observed in the study?

The study highlights the role of dendritic cells (DCs) in initiating immune responses, noting that DCs migrated more effectively to the draining lymph nodes in older mice. This suggests that the ability of DCs to trigger allergic sensitization increases with age. IL-33, an inflammatory molecule released by skin cells, was also found to play a vital role in skin sensitization. Tape-stripping induced IL-33 expression in the skin, with levels increasing with age. Further research is needed to fully understand the complex interplay between DCs, IL-33, and other immune factors in the development of food allergies.