A Kiss Before Sneezing

About 7 million Americans are allergic to one type of food or another--from nuts to milk to wheat to shellfish. This year, some 30,000 will develop reactions severe enough to send them to the emergency ward, and about 200 will die--often after their throats close up and their blood pressure plummets.

But you don't have to eat anything to have an allergic food reaction. Some people are so sensitive that touching food briefly or inhaling microscopic particles is enough to do the trick. "It can take a surprisingly tiny amount to elicit a reaction," says Dr. Suzanne Teuber, an allergist at the University of California at Davis.

Teuber published a report in the New England Journal of Medicine last week on the role kissing plays in triggering food allergies. It turns out that a surprising number of people who are allergic to peanuts have had bad reactions--in one case, severe enough to be sent to the hospital--from smooching with someone who'd been eating the nuts.

Most of the reactions Teuber and her co-authors describe were mild: itching, swelling and wheezing. But allergies can be additive: repeated exposure to even tiny quantities can cause the body to react more aggressively each time. That's why a series of mild rashes will sometimes escalate into severe breathing problems and even shock.

What complicates matters is that different types of allergies can feed on one another. Ragweed and certain melons, such as honeydew and cantaloupe, for example, share a common allergy-provoking protein. If the body is already churning out antibodies to ragweed, eating a melon can rev up the process even further, leading to itching and swelling of the mouth. Similarly, people who are allergic to latex can get a reaction from eating such fruits as bananas and kiwis, because of a common allergen.

If you have a bad food allergy, a little precaution can go a long way. If your eyes water or you start to wheeze just from smelling certain foods, don't be afraid to ask the people you live with to avoid handling them or to wash their hands if they do. Your friends should probably also brush their teeth before any intimacies begin.

For most people, reading food labels is usually good enough; two-thirds of food-allergy reactions come from inadvertently ingesting the offending ingredient. But though the Food and Drug Administration requires manufacturers to list all potential allergens, from nuts to eggs to fish, they don't always comply. In March, a Hauppauge, N.Y.-based cookie company had to recall some chocolate-chip cookies because it had neglected to mention that peanuts were an ingredient, and its customers were getting sick.

And then there are those allergens that turn up where you have no reason to expect them. New York University allergist Dr. Clifford Bassett has traced several cases of unexplained rashes on the faces of children to food oils in the shaving cream their fathers used before kissing them on the cheek.

For more, visit foodallergy.org or e-mail alcpark@aol.com