Although 25 of every 100 people in America believe they are allergic to certain foods, the truth is that food allergies are rare occurrences, doctors say.

Between 6 million and 7 million people suffer from food allergies, which is far less than the 35 million people who suffer from hay fever or spring allergies.

But for the person with a food allergy, symptoms can be much worse than just suffering from sneezing and itchy, watery eyes every spring. Food allergy symptoms include rashes, breathing or cardiac problems. Severe cases can be deadly.

More children than adults suffer from food allergies, and milk and peanuts are the most common causes. Children often have more allergies because their immune systems aren't as fully developed, but they can grow out of an allergy as time passes. Also, if children have parents who are allergic, then the children are susceptible to having an allergy.

The most common foods that trigger allergic reactions are milk, peanuts, tree nuts like walnuts, soybeans, wheat, fish, shellfish and eggs.

When people have food allergies, their immune system responds to what it believes is a harmful substance in the body by releasing chemicals that trigger allergic symptoms: rashes or breathing difficulties or digestive problems.

There is no cure for food allergies; avoidance is the best prevention.

Terra Aufdenberg, 24, of Jackson, Mo., learned quickly that she's allergic to pecans and walnuts. After shelling pecans eight years ago, Aufdenberg's hands swelled and she had trouble breathing. She was allergic to the oils in the pecans.

It was the first time she'd had any reaction to the nuts, and walnuts cause her to react the same way. But now she's forced to do without any nuts in her foods.

"I carry Benadryl with me and just have to be careful," she said.

Stopping by a barbecue booth at the Oklahoma State Fair last year, Aufdenberg tried a slice of beef brisket. Her tongue started to feel thick and she began to feel ill. She asked someone what the meat's sauce included. It turned out to be a pecan rub.

"I never would have thought about that," said Aufdenberg, a registered nurse. Chopped nuts are often hidden in foods or desserts, which can pose lots of problems for people who are allergic.

Kelsie Whitworth, 9, of Fruitland, Mo., knows which foods are off limits because of her allergy. She breaks out in hives and vomits excessively if she eats eggs, which means no cakes, cupcakes or cookies as snacks.

Kelsie remembers being really sick from eating a pinch of angel food cake when she was a toddler. She was just able to reach the cake on the table and tore off a bite. She broke out in hives and vomited for nearly an hour.

An allergy test later confirmed that eggs were to blame.

"Now we avoid them at all costs," said Dana Abel, her mother.

But finding the problem food can be tricky. Some ingredients or derivatives can be hidden in food labels, listed under different names or as the chemical ingredient.

"When we go to the grocery store I read the label on everything we buy," Abel said.

That's because eggs aren't the only problem foods for Kelsie. She can't eat peanuts, soybeans or wheat products. Her other food allergies don't create reactions as severe as the eggs.

But Abel has learned how to modify some recipes so she can bake desserts for her family. She can substitute vinegar in place of eggs in a cake recipe or fruit juices are acceptable.

Since Kelsie had to make such adjustments to her diet, it was easier for the whole family to make the same changes.

"If it's something she can't have, then we just don't buy it," Abel said. "That way I know she won't go to the cabinet and grab something she can't have." But it's not always that easy making sure Kelsie, or any child with a food allergy, doesn't come in contact with something they cannot eat. Parents should notify teachers and school nurses about potential allergy problems.

At school, Kelsie can't share treats brought in for class parties unless it's a product without eggs. Kelsie said her third-grade class at North Elementary School just had a party for learning its multiplication tables. But her teacher, forgetting about the allergy, brought a cake for the class to eat. "I got a sucker because it had eggs," Kelsie said.

Kelsie takes her lunch to school about two or three times a week because the cafeteria serves something with eggs or wheat. But this week, she's been able to eat lunch at school most days.

"I think this is the first time since kindergarten that she's been able to," Abel said.

Kelsie doesn't mind much that she has a limited diet -- potato chips and granola bars are her favorite snacks -- and neither does her mother, who says eliminating eggs was tough at first.

"You learn to do without and after a while you don't think about it," Abel said. "It's like going on a diet."

But some people will limit their food intake because they think they have an allergy when their body is simply intolerant of that food. Many people say they are allergic to milk when they truly only have problems digesting it, said Lori Pettet, a dietitian at St. Francis Medical Center.

Even without a medical diagnosis, it's probably best to avoid the foods if you know they cause problems, said Dr. Gary Olson, a pediatrician who has seen dozens of children with food allergies during his 20 years in practice.

Some food allergies can be outgrown, like milk allergies or even peanuts. Olson often re-introduces infants to milk after they reach age 1 if they've had problems earlier. Infants with milk allergies drink soy-based or non-milk based formulas.

But there are some allergies so severe that any consumption is dangerous. Peanuts tend to trigger more dramatic reactions than milk, Olson said.

If that's the case, Olson said, it's best to try re-introducing foods while making a visit to an allergist in case reactions are severe.

Food allergies tend to run in families, and children are usually allergic to fewer than four different foods.

Asthma and hay fever allergies also are common in families with food allergies.

"If you have a family history then you should be more careful and watchful," Pettet said. Toddlers should be introduced to new foods one at a time so that parents can check for reactions.

People who suspect a possible allergy should keep a diary of the foods they eat and the reactions they cause. That information can be helpful to a doctor making an allergy diagnosis, Pettet said.

Kelsie visited an allergist and went through 48 separate tests to determine what she was allergic to, but after the 48th test, Abel said her daughter had suffered through enough.

"She knows what she can have and what she can't," Abel said.

ljohnston@semissourian.com

335-6611, extension 126