The U.S. Centers for Disease Control and Prevention reports that food allergies in children have increased by approximately 50% since 1997. This equates to roughly two children per classroom. The factors appear to be varied and the research is limited.
However, a new study published in the Journal of Allergy and Clinical Immunology attempts to explain high-risk profiles for persisting allergic diseases.
According to the researchers at National Jewish Health behind the new report, over five million children currently suffer from some kind of allergy–with cases of eczema, food allergies, asthma, and hay fever rising steadily in the last decade.
These conditions can be linked via a typical progression known as atopic march.
The natural history of allergic disease develops over the course of infancy and childhood and often begins with dermatitis. This is due to an excess of a bacteria called staph aureus. This same excess dramatically reduces an infant’s ability to fight off infections.
“Classically, the atopic march begins with atopic dermatitis (AD), and progresses to IgE-mediated food allergy (FA), asthma, and allergic rhinitis. Each of these conditions carries complex pathophysiology involving multiple facets of the immune system,” a recent critical-evidence and relevance report concluded.
“For example, AD was once considered a manifestation of atopy itself but is now thought to result from a combination of primary skin defect(s) and underlying genetic or environmental propensity to develop type 2 inflammation. While non-type 2 inflammation likely contributes to AD pathophysiology, for the purposes of this review we will focus on the role of type 2 inflammation, as it is the central tenet of the atopic march.”
Although many of the mechanisms remain unknown, the authors of the new paper theorize that babies born in autumn are at a higher risk of developing a life-long allergy compared to the rest of the population.
To properly assess their results, an in-depth review of clinical trials conducted on pregnant women and their children followed the published findings.
In it, the researchers intend to control for factors like living environment, genetics, medications, and products in the home in service of developing countermeasures during the atopic march process.
The authors are confident that early intervention will be the key to mitigating rising allergic disease incidences in the future.
“We looked at every child treated in our clinic, and those born in the fall were much more likely to experience all of the conditions associated with the atopic march,” Jessica Hui, MD, a pediatrician at National Jewish Health and lead author of the study wrote. “Now we are learning more about why that is and we strongly believe it stems from the bacteria on the skin on how they affect the skin barrier. When food particles are able to penetrate the skin rather than being digested, the body sees them as foreign and creates antibodies against them, which causes the child to become allergic.
“We think if we can intervene at a very young age, even right after the baby’s out of the womb, then potentially that’s a way for us to try to stop the development of this atopic march,” Dr. Hui concluded.