Pet exposure may cut child risk of allergies, study shows

Detroit-Children who grow up with cats or dogs may be lesslikely to suffer from pet-specific and other allergies, according to a studypublished in the Journal of the American Medical Association (JAMA).

The Henry Ford Hospital study, funded by the National Institutesof Health, is believed to be the first in the United States to show that earlyexposure to pets has a protective effect on developing pediatric allergies. Itadditionally showed children who live with pets may be less susceptible toragweed, grass and dust mite allergies.

The 10-year study, published in the Aug. 28 issue of JAMA showedthat children exposed to two or more cats or dogs during the first year of lifewere half as likely to develop common allergies at ages 6 or 7 than those notexposed to pets.

Children exposed early to pets had overall lower antibody levelsand fewer positive skin test reactions to dog, cat, ragweed, grass and dustmite allergens.

"This study indicates that having a pet around when a childis very young may influence the development of a child's immunesystem," says Christine Cole Johnson, Ph.D., co-principal investigatorand senior research epidemiologist for Henry Ford Hospital.

Johnson says researchers theorize that exposure to cats and dogsmay influence the development of a child's immune system through exposureto endotoxins, bacterial products commonly associated with the presence ofpets.

For the study, researchers followed 474 children born between1987-1989 (242 girls; 232 boys). Data was collected prenatally, at birth and atregular intervals until the children were 6 and 7 years old. The study includedblood tests that measure antibodies that cause allergies; skin reaction teststhat show whether a person is hypersensitive to an allergen; and a pulmonarytest that estimates the reactivity of the airways.