"An estimated  percent of Americans have food allergies http and the Centers for Disease Control and Prevention has concluded that allergies are a growing https public health concern. But diagnosing allergies can be tricky and kids can outgrow them too. Now a new study https sheds light on the effectiveness of a test called a food challenge https to determine whether a person can tolerate a food they once reacted to. Jula Cieciuch a fifthgrader who lives in Telluride Colo. recently took a food challenge to find out if she was still allergic to eggs. When she passed she was ecstatic. After years of avoiding all foods with eggs she was a bit shocked. For so long it was You cant eat this. You cant eat this Jula says.  I was very emotional Shes also outgrown allergies to walnuts and almonds. Its a huge relief ... it has really opened up her diet  a lot her mom Kendall Cieciuch told us. Once you can eat eggs you can eat cakes and breads and frittatas and lots of other baked goods. Article continues after this message from our sponsor Jula is still allergic to some foods including milk and cashews so she still needs to be careful. But Kendall says every time shes crossed a food off her allergy list it makes life a little easier. Jula Cieciuchs story is not uncommon. About  to  percent of children with an egg allergy will outgrow it. And about  percent of kids outgrow peanut allergies. In Julas case her allergists at National Jewish Health in Denver Colo. repeated the standard allergy blood tests last summer. Thats when they realized she may have outgrown her egg allergy.   The blood test measures the levels of a certain type of antibody immunoglobulin E IgE httpkidshealth.orgenparentstestimmunoglobuline.html. The higher the level the more likely a person is to have an allergic reaction. Julas blood revealed a drop in antibody count.  But the only way to confirm that it was safe for Jula to eat egg was to take the food challenge test. Basically the test entails eating small quantities of the foods youve been allergic to. The testing is done under medical supervision. What they do is give you a really small dose like a crumb basically explains Jula. Then after  minutes or so if you dont have any reaction you can take a dose thats a little bigger. If you can eat an entire egg you pass. A new study published https in the Annals of Allergy Asthma  Immunology illuminates just how many people come to find out they can eat foods theyve long avoided.   Researchers studied the results of about  food challenges. The tests were done in adults and children whom doctors suspected had become tolerant to foods theyd once reacted to.  We found that  percent of the patients challenged had mild or moderate allergic reactions explains study author Carla Davis https an allergist and director of the Food Allergy Program at Texas Childrens Hospital. If the symptoms were treated with just Benadryl or another antihistamine they were considered mild or moderate. She says  percent of the reactions were more serious requiring treatment with epinephrine. But the vast majority of patients  percent did not have an allergic reaction. In other words they tolerated the food just fine. She says the results arent that surprising since allergists had classified these patients as lowrisk for reacting to the foods they were being tested for.  I think the results are very encouraging Bruce Lanser https a pediatric allergist who directs the Pediatric Food Allergy Program at National Jewish Health in Denver told us. He was not involved in the study but he says the findings mirror what he sees in his clinical practice. We know a certain percentage will outgrow their allergies Lanser says. And the last thing I want to miss is the opportunity to get a food into a kids diet. He says many of the patients in the study may have outgrown their allergy just like Jula did. But its also possible some of them never truly had a food allergy. As weve reported http people sometimes misinterpret the symptoms of a condition such as lactose intolerance for a food allergy. Lanser says it can be tricky to diagnose food allergies. Thats because the two main tests doctors use  the blood test and the skin prick test  only reveal part of the story. Both tests only measure sensitization he explains. All they can tell us is how likely you are to react when you eat the food.  And thats where the oral food challenge comes in. Its become the gold standard test to rule out an allergy.  So if you or your child tested positive for a food allergy years ago you may want to consider seeing an allergist again."