Pets Won't Avert Allergies
Contrary to commonly held beliefs, pet
avoidance doesn't stop kids from developing allergies to animals,
new research contends. In fact, exposure to pets might actually
be a better hindrance, the researchers say.
A study of Swedish children found
that while being allergic to cats was the most common airborne
childhood allergy, keeping cats didn't necessarily increase the
risk of developing allergies in 7-to-11-year- olds.
"Our research has found no
increased risk of sensitization in children due to exposure to
pets in the home," says study author Eva Rönmark. "Sensitization
is genetic, and the big risk factor for getting it is if you already
have it in your family." If that's the case, she adds, it's
wiser not to keep pets in the home.
The joint Swedish-U.S. study found
that children who had continuously owned cats or dogs actually
developed less allergies to them than new pet owners, or those
who had only been exposed earlier in life; among children who
were allergic to cats, 80 percent had never kept a cat at home.
Rönmark, an allergy expert
at the Department of Medicine at the Central Hospital of Norrbotten
in Lulea-Boden, Sweden, and colleagues from the University of
Virginia at Charlottesville conducted the research. They studied
2,454 children in Northern Sweden, 7 and 8 years old, on a yearly
basis, and gave them skin sensitization tests every four years.
Parents were also asked to complete
annual questionnaires on their children's risk factors.
"Parents need to be aware
also, that just because you don't have a pet, your child won't
develop sensitization," adds Rönmark. "Cat [and
other] allergens can also be found where there are no cats --
for example, in schools, where they can be transferred by clothes."
The study found persistently high
exposure to cat and dog allergens appeared to protect both boys
and girls equally from developing allergies.
"If there are symptoms of
sensitization, of course you should not keep the cat, and [that]
can be sometimes difficult for kids," says Rönmark.
"But at this time, though, we don't really know why these
high exposure levels decrease the risks."
Researchers note that when a child
with an existing allergy comes into contact with a cat or dog,
naturally they begin to show more symptoms. Traditional thinking
had been to assume that avoiding pets altogether would prevent
The study suggests the new findings,
published in the October issue of the Journal of Allergy and
Clinical Immunology, are antithetical to the traditional views
that exposure causes more severe symptoms.
"Studies we have done show
that exposure to microorganisms has been shown to play a role
in protecting against developing allergies," says medical
researcher Marjan Kerkhof of the University of Groningen in the
Netherlands. "And pets certainly would carry a lot of microorganisms."
"We've found that even during
pregnancy, babies born to mothers who have pets in the house tend
to have a lowered levels of IgE (immunoglobulins)," she says.
"High IGEs have been shown to be a risk factor for developing
"But then," she cautions,
"exposure to allergens seems to increase the risk of developing
allergies. So there are two mechanisms at work -- on the one hand
exposure to microorganisms has a protecting effect, but on the
other allergens can elevate the risk. So there is only speculation
at this point, not real proof. So I think there needs to be more
work done on this subject."
Learn about cutting down on pet
and other indoor allergens from the American
Academy of Allergy, Asthma and Immunology and the Nemours
Reference Source 101