Using data from about 2,500 Canadian children, the researchers assessed
the presence of atopic dermatitis and allergic sensitization in children as
young as one year old. When the children were three years old, the researchers
conducted a clinical evaluation for the presence of bronchial asthma, allergic
rhinitis, food allergies, and eczema.
One-year-old children who have eczema or atopic dermatitis and are allergic to
an allergen are seven times more likely than other children to develop asthma
and food allergies by the age of three, the researchers concluded. This work
will help doctors better predict which children are likely to develop asthma
and allergies. It has long been known that infants with eczema or atopic
dermatitis are more likely to develop asthma and allergic rhinitis later in
life, a phenomenon known as the “atopic march.” But it was difficult
to predict which children with eczema would develop these problems in the
future. It was found that having only eczema, without sensitivity to allergens,
does not significantly increase the risk of developing asthma in children. The
results of the study help to understand the association of atopic dermatitis
and early allergic sensitization with the risk of asthma and food allergies and
show that, in combination, they pose a significant risk of future allergic diseases.
Two thousand three hundred children participated in the study. The collected
data made it possible to assess the presence of eczema and sensitivity to
allergens at the age of one year. When the children were three years old, the
researchers conducted a clinical evaluation to determine the presence of
asthma, allergic rhinitis, food allergies, and atopic dermatitis. The combined
effect of eczema and allergic sensitization has been found to be greater than
the sum of their individual effects on both asthma risk and food allergy.
There are certain genetic variants known to be risk factors for developing
allergies, but genotyping is not widely used in clinical practice, and this
study offers healthcare professionals an alternative method for identifying children
at risk. The findings are based on another study that found that children who
avoid cow’s milk products, eggs and peanuts during the first year of life are
at increased risk of allergic sensitization to these products later. As the
authors noted, much of what happens to us later is related to the risks we face
in early childhood.