There is a widely accepted theory, called the allergic march, that says if a child has eczema they’re more likely to develop a food allergy by age 5 and then asthma or hay fever by age 10. Eczema is usually the first allergic disease a child will develop, often as a baby.
But determining whether a child will develop additional allergic diseases could be more complex than the sequential march.
“Your genetic and environmental background might factor into the allergic diseases you develop,” says Amy Eapen, M.D. M.S., a pediatric allergist and immunologist at Henry Ford Health. “For example, exposure to pollution can increase your eczema risk but prenatal exposure to a dog can decrease your risk. Risk for allergic diseases can also vary by ethnicity or race. In fact, Black children are more likely to develop eczema than white children, and other subgroups also have varying risk.”
Most research confirming the allergic march theory, however, has mostly included white children. So Dr. Eapen and her team conducted a study with people from suburban and urban Detroit – 68% of whom self-identify as Black – and the results didn’t quite fall in line with the allergic march theory.
“We found that kids who had a history of food allergies were more likely to develop hay fever, whether or not they had eczema,” says Dr. Eapen. “Kids who didn’t have eczema – and who had a food allergy – were more likely to develop asthma by age 10 than kids who had eczema. Kids who tested positive to indoor and outdoor allergens (dust, animals, pollen, etc.) were also more likely to develop asthma if they didn’t have eczema.
“We still think these allergic diseases are linked, but how they’re linked is a bit more complicated and this study shows that. It’s not like having eczema definitively determines you’ll develop both food allergies and asthma.”
Being Proactive About Eczema
Some children eventually outgrow eczema while others don’t. Children who develop severe eczema in early infancy are less likely to outgrow it, says Dr. Eapen. Same with food allergies, asthma and hay fever: some children eventually outgrow these diseases while others deal with them lifelong.
But if your baby does have eczema, it doesn’t hurt to be proactive about other allergic diseases they may develop in the future.
“While we don’t recommend allergy testing just because your baby has eczema, it may help to see an allergist to discuss their risk for other allergic diseases,” says Dr. Eapen. “An allergist might recommend introducing highly allergenic foods like peanuts early on. The earlier they’re introduced, the less likely it is that your child will be allergic. Talk to your pediatrician to see if they recommend this.
“We can’t test for some of these allergic diseases that early on. Very rarely do babies have asthma or hay fever within the first few months of life. But the presence of eczema and/or food allergies can keep you alert to any respiratory issues that may develop as your child gets older.”
Reviewed by Amy Eapen, M.D., M.S., a senior staff allergist who sees pediatric patients at Henry Ford Hospital in Detroit, Henry Ford Medical Center – Columbus, Henry Ford Medical Center – Fairlane and Henry Ford Medical Center – Sterling Heights.