As mentioned in this month's Allergy Consumer Report, I recently had my second child, a sweet little boy. Of course, I'm always interested in topics about allergies and children, and an article entitled Family Dog Tied to Lower Eczema Rates in At-Risk Kids caught my eye.
According to research conducted by Dr. Tolly G. Epstein of Ohio University's Cincinnati College of Medicine and others and published in the Journal of Pediatrics, living with a dog starting in infancy may make young children less likely to develop eczema. Conversely, among children with a sensitivity to cat allergen, living with a cat may increase the odds of eczema.
In the study, children under one year of age who were at increased risk of allergies were given yearly exams that included skin-prick tests to evaluate sensitization to a number of allergens. This determined which allergens the body had produced antibodies against. The research team found that 14 percent of the children had eczema by the age of four. However, among the children who had a dog in their home during infancy, the rate was only 9 percent. In addition, among children who did have a sensitivity to dog allergen, the risk for developing eczema was substantially lower among children who had a dog compared to those who didn't.
With cats, the issue was not as clear-cut. No overall definitive relationship between having a cat and lower eczema risk was found. However, among children sensitized to cats, there did appear to be some association: The rate for developing eczema was highest among those with a cat allergen sensitivity who had a cat compared to those who didn't and lowest among those with no cat sensitivity who did have a cat.
Although there isn't currently a solid explanation for the apparent protective effect of having a dog, Dr. Epstein speculates that early exposure to dog allergen affects children's immune system to develop in a way that eczema is less likely to occur. ‘It may be that these children develop a tolerance, but we don't know that for sure.’
Complicating the overall picture even further, these findings seem at odds with those of another study that correlated increased asthma risk with the presence of a dog in the house among children at increased allergy risk. (Cats were unrelated to asthma risk.) This could be due to the fact that dogs carry more endotoxin, a bacteria that triggers inflammation in the airways, than cats do.
Ultimately, Dr. Epstein says that at this point it is hard to give parents specific advice on pets and also points out that little is known about how family pets affect allergy and asthma development in children with average risk of these conditions.
These studies fit in perfectly with the ongoing exploration of whether exposure or protection from certain allergens is a better forestaller of allergic conditions. Since my family is not at increased risk for allergies and asthma and we have both a dog and two cats, I hope that if anything, my children's exposure to dog and cat allergen helps their bodies know that these are not particles that need to be fought against.