Peanut sensitive?

Allergy linked to wealth,

“Overall household income is only associated with peanut sensitization in children.”

DR. SANDY YIP LEAD AUTHOR OF STUDY

If you’ve got a big bank account, your children are more likely to have a peanut allergy. That’s according to a U.S. study that found more children in higher-income families had peanut allergies.

The findings, say researchers, support the hygiene hypothesis: Environments that are too clean and sterile can suppress the immune system’s normal development and boost a child’s chances of developing allergies.

In other words, a squeaky clean house may put kids at risk.

“Overall household income is only associated with peanut sensitization in children,” the study’s lead author, Dr. Sandy Yip, said in a statement. (She could not be reached for an interview.)

“This may indicate that development of peanut sensitization at a young age is related to affluence, but those developed later in life are not,” said the allergist and U.S. air force major. The findings are part of a poster presentation at an annual meeting of the American College of Allergy, Asthma and Immunology, being held in Anaheim, Calif. It ends on Tuesday. Researchers examined U.S. health data from 2005 to 2006, looking at socio-economic status and peanut sensitization. Of the 8,306 people examined, 776 had an elevated antibody level to peanuts (a measurable sensitization to peanuts, but not necessarily a clinical peanut allergy). When they homed in on the children, aged1to 9, those from families with higher incomes showed greater sensitization to peanuts. But linking this to the hygiene hypothesis may be a big leap.

Dr. Susan Waserman, allergist and clinical immunologist at McMaster University, called the findings interesting. But, she said the “troubling” hypothesis linking peanut allergy to income warrants rigorous study.

“Just because someone is in a higher socio-economic status doesn’t mean they live more cleanly,” said Waserman. She added, “It’s offensive” to suggest lower-income families may not live in clean homes.

Perhaps, she said, people with higher incomes have greater access to allergists, better medical care, or read more about allergies, making them more inclined to get their children assessed.

“All of these things that contribute to this hypothesis have not been measured, so you can’t really make that assumption.”

According to the non-profit organization Anaphylaxis Canada, peanut allergies affect about two in 100 children, and the prevalence is rising.