Year-old infants who have a skin disease known as atopic dermatitis, and who are prone to allergies, are seven times more likely to develop asthma., a Canadian study finds.
They are also prone to developing a food allergy by the time they are 3, researchers said.
Both findings were from the Canadian Healthy Infant Longitudinal Development (CHILD) study.
The CHILD researchers published their work in the Journal of Allergy and Clinical Immunology. It is titled “Predicting the atopic march: Results from the Canadian Healthy Infant Longitudinal Development Study.”
Scientists have know for some time that there is a strong likelihood of an infant with eczema or atopic dermatitis developing asthma and hay fever as a child. But it has been difficult to predict which infants with atopic dermatitis were certain to develop these conditions.
To try to shed light on the matter, researchers looked for a connection between atopic dermatitis and vulnerability to allergy in 1-year-old infants. They did this with 2,300 infants in the CHILD study.
The team assessed the children at age 3 to determine whether they had asthma, hay fever, a food allergy or atopic dermatitis.
They found that children who had atopic dermatitis and who were prone to allergies were at greater risk of developing asthma. Atopic dermatitis alone, without allergy susceptibility, did not significantly increase a child’s risk of developing asthma.
“These findings help us to understand the interactive effects of AD [atopic dermatitis] and early allergic sensitization on the risk of asthma and food allergy, and show that in combination they pose a significant risk for future allergic disease,” Malcolm Sears, the founding director of the CHILD study, said in a news release. He is a professor of medicine at McMaster University in Hamilton, Canada, and a researcher at the Firestone Institute for Respiratory Health at St. Joseph’s Healthcare Hamilton.
Although genetic mutations are known risk factors for an allergy, few allergy and asthma doctors use genetic analysis in their practices.
The Canadian reearchers’ discovery can help doctors predict which infants will develop allergies and asthma without using expensive genetic testing.
A key food allergy finding in the study was that children who are not fed milk products, eggs, and peanuts are at increased risk of becoming allergic to them later on.
“Much of what happens to us later in life is related to the exposures we encounter in early childhood,” Sears said.
Early exposure to a variety of food reduces a child’s risk of food allergies later, researchers said.
“Governments are realizing that we cannot learn about healthy aging if we don’t understand what happens to a child during the first few years of life and even to the mother during pregnancy,” said Judah Denburg, a professor of medicine at McMaster University who is also CEO of AllerGen NCE, the national research network funding the study.
“That’s why CHILD, which has been following 3,500 Canadian children and their families from before birth, has such enormous value in answering questions about the origins of chronic diseases,” Denburg said.