Study: Predicting Which Children Are On The 'Atopic March'

Doctors have long known about the ‘atopic march’, the progression of symptoms in some infants with atopic dermatitis (eczema) who develop asthma and allergic rhinitis later in childhood. But predicting exactly which children will go on to develop these conditions has been difficult.
New findings published in the Journal of Allergy and Clinical Immunology (JACI) will provide doctors better predictive capabilities. The findings stem from the Canadian Healthy Infant Longitudinal Development (CHILD) Study, a birth cohort study following 3,500 Canadian families and their children to help determine the root causes of chronic diseases such as asthma, allergies and obesity, among other conditions.

Researchers analyzing the records of 2,311 children enrolled in CHILD came to the following conclusions:

• Infants with both eczema and allergic sensitization were seven times more likely to develop asthma symptoms by the time they turned 3 compared to children without either condition. Infants with eczema only (no sensitization) were not at increased risk of asthma.
• Infants with only eczema or allergic sensitization were at somewhat higher risk of developing allergic rhinitis, commonly known as hay fever. But infants with eczema and allergic sensitization were nearly 12 times more likely to develop allergic rhinitis, compared to children without either condition.
• The presence of both eczema and allergic sensitization in infancy also greatly increased the risk of developing a food allergy by 3 years of age. Specifically, sensitization to food allergens, as opposed to pollen or other aeroallergens, and eczema had additive interactive effects on the rate of food allergy.
• While infants with eczema and allergic sensitization at 1 year were six times as likely to also have eczema at 3 years of age, there was no evidence of an interactive effect on the risk of the disease.

“It’s common for children to develop atopic dermatitis in infancy, with an estimated 10 to 20% of children worldwide suffering from the disease,” said senior author Malcolm R Sears, MB, FAAAAI. “We found that assessing allergic sensitization using common skin tests in combination with atopic dermatitis substantially improved the prediction of all four allergic outcomes we studied.”