Food Allergy Myths and Facts
Myth No. 2: Children never outgrow food allergies.
"Somewhere around 90% to 95% of kids outgrow dairy, egg, wheat, and soy allergies," McMorris says. That used to happen by the time they started school, but that's not necessarily the case anymore. Research suggests children now take longer to outgrow milk and egg allergies, though the majority are allergy-free by age 16.
The chances that your child will outgrow a shellfish, tree nut, or peanut allergy are much lower, a study suggests.
Myth No. 3: Most food allergies are caused by additives such as artificial colors and flavorings.
"Absolutely a myth," McMorris says. It's true that some reactions to additives are similar to those caused by food allergies. Nitrates, for instance, can cause hives and itching. And red and yellow food coloring have been linked to anaphylaxis.
The actual allergy triggers are the proteins in the food, McMorris says. Food additive intolerance is rare. Less than 1% of adults have it.
Myth No. 4: Most serious reactions from a food allergy are caused by peanuts.
Any food you're allergic to could cause a serious reaction, whether it's peanuts, tree nuts, milk, eggs, wheat, soy, fish, or shellfish. Those eight foods make up 90% of food allergies in the U.S. All of them have the potential to be life-threatening, McMorris says.
Myth No. 5: You only need a blood test to diagnose a food allergy.
Blood tests can sometimes be misleading. They may have a result called a "false positive." In other words, it says you're allergic when you're really not. How often does that happen? A whopping 50% to 75% of the time, McMorris says.
To get a clear diagnosis, an allergist may do something called a "food challenge." He'll give you small doses of a food and watch you to see if you get an allergic reaction. If there are no symptoms, he'll gradually increase the amount. Still no signs of trouble? You're declared allergy-free.
"Food challenges can confirm that somebody actually has a food allergy," McMorris says. "They're also used to see if someone has outgrown a food allergy."