Dog Ownership May Help Prevent Eczema in Children with Dog Allergies

Cincinnati—Parents may want to reconsider their choice of pet: New research shows that children with eczema may actually benefit from living with a dog during infancy.

Eczema is a chronic skin condition that causes extreme dryness and irritation, most often occurring during childhood.

"The number of children with allergic eczema is rising, but the reasons for this are unclear,” explains Tolly Epstein, MD, corresponding author of the study and assistant professor at the University of Cincinnati (UC) College of Medicine. "Our research suggests that exposure to dog allergens early in life may actually have a protective effect against developing future allergies among a high-risk population.”

In a recent examination of the relationship between pet ownership and eczema, a collaborative team of UC and Cincinnati Children’s Hospital Medical Center researchers found that children who tested positive for dog allergies were less likely to develop eczema by age 4 if they lived with a dog prior to age 1. Conversely, children with dog allergies who did not have a dog in the home were four times more likely to develop eczema.

Epstein and her colleagues from UC and Cincinnati Children’s report their findings online ahead of print Sept. 30, 2010 in the Journal of Pediatrics.

Researchers gathered data from 636 children enrolled in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), a long-term epidemiology study examining the effects of environmental particulates on childhood respiratory health and allergy development. Children enrolled in the study are considered at high risk for developing allergies because they were born to parents with allergies. 

The current study specifically examined the relationship between dog and cat ownership and risk for developing eczema. From birth, children were tested annually for 17 different allergies—including to foods, aeroallergens (i.e., pollen, mold) and environmental exposures such as diesel particulates. Parentsalso completed annual surveys about their child’s illness and allergic symptoms.

Unlike dog ownership, cat ownership seemed to have a negative effect on children with cat allergies. 

"Children who owned a cat before age 1 and were allergic to cats based on allergy skin testing were 13 times more likely to develop eczema by age 4,” explains Epstein. "However, children who were not allergic to cats were not at an increased risk for eczema if they owned a cat.” 

Epstein hopes that these findings can help parents of children at high risk for developing eczema when choosing a family pet.

Other collaborators in the study include David Bernstein, MD, Linda Levin, PhD, Gurjit Khurana Hershey, MD, PhD, Patrick Ryan, PhD, Tiina Reponen, PhD, Manuel Villareal, MD, James Lockey, MD, MS, and Grace LeMasters, PhD, principal investigator of the CCAAPS.