Study Reveals How Having a Dog May Lower Baby's Eczema Risk

Atopic eczema is a chronic, usually hereditary, inflammatory skin condition that affects almost 20 percent of babies. Though common and treatable, eczema is often itchy and irritating, with American parents spending thousands of dollars on creams, ointments and other treatments for baby every year. But what if you could lower baby’s risk of developing eczema just by bringing a furry friend into your home?

A new study from the University of Edinburgh explored how various environmental factors—from breastfeeding and smoking to pet ownership and hygiene habits—might influence a baby’s risk of developing eczema. Researchers tested for interactions between the 24 most significant eczema-associated genetic variants and 18 early-life environmental factors during pregnancy and the child’s first year.

Looking at the DNA of over 250,000 people, researchers found that a specific genetic variant linked to a higher risk of eczema was significantly impacted by dog ownership. In babies with this gene, exposure to a dog during thier first year of life appeared to nearly eliminate their risk of developing eczema.

To figure out how this worked, researchers dug deeper and found that the gene in question is linked to a protein called IL-7R, which plays a role in immune function and skin inflammation. In lab tests, when skin cells with this variant were exposed to molecules from dogs—like tiny particles from their fur or skin—those signals, which might normally trigger allergies, actually helped calm inflammation.

“The most difficult questions I’m asked by parents in clinic are about why their child has eczema, and how they can help. We know that genetic make-up affects a child’s risk of developing eczema and previous studies have shown that owning a pet dog may be protective, but this is the first study to show how this may occur at a molecular level,” Sara Brown, a professor at the University of Edinburgh Institute of Genetics and Cancer and one of the study’s authors said in a press release. “More work is needed, but our findings mean we have a chance to intervene in the rise of allergic disease, to protect future generations.”

The study also noted a similar protective effect in young children with older siblings, though more research is needed to confirm that link. Scientists believe that early exposure to a wide variety of bacteria—whether through pets or siblings—may be part of what’s helping to train the immune system in a protective way.

Researchers believe that by looking at things on a molecular level, they may be able to help pinpoint exactly what exposures might be helpful to baby. “This study sheds light on why some children develop eczema in response to environmental exposures while others don’t,” added the study’s lead author, Marie Standl, PhD. “Not every preventive measure works for everyone – and that’s precisely why gene–environment studies are crucial. They help us move toward more personalized, effective prevention strategies.”

This isn’t the first time dog ownership has been praised for its benefits to baby’s health. Other studies have linked having a dog to a lower risk of obesity, fewer allergies and even stronger immune function. See five science-backed ways dogs can benefit baby and tips to help your pet bond with baby.