Many people don't realize allergies and asthma go hand-in-hand, and about 90 percent of kids with asthma also have allergies. Even more important, when asthma is undiagnosed or poorly controlled, children are at risk for suffering difficult-to-treat allergic reactions to food.

According to a study presented at the American College of Allergy, Asthma and Immunology (ACAAI) Annual Scientific Meeting, a two and-a-half year-old girl in Pennsylvania suffered a life-threatening allergic reaction (anaphylaxis) to eating an orange - the first time such a case has been reported in a toddler.

"She ate an orange, and within a few minutes had developed severe anaphylaxis," said allergist and ACAAI member Sigrid DaVeiga, MD, study author. "Her lips and tongue swelled, she broke out in hives and couldn't breathe well. Her parents immediately got her to an emergency room, and she was flown by helicopter to a pediatric intensive care unit."

Following treatment and a 48-hour hospital stay, the girl recovered and was able to go home. Upon examination of her medical history, doctors discovered that she had previously had orange juice with no reaction, but more importantly, that she had undiagnosed asthma. Later testing by allergists found that she was allergic to both orange and peach.

"Several recommendations were made following the allergic reaction, said allergist and ACAAI member Sayantani Sindher, MD, study author. "She was advised to avoid orange and peach, and also told to start asthma therapy, both of which will keep future allergic reactions under control."

According to ACAAI, it's very rare for anyone to have a severe allergic reaction to an orange.

It's more common for people who suffer from hay fever to sometimes suffer from oral allergy syndrome - an itchy mouth or scratchy throat after eating certain raw fruits or vegetables and some tree nuts. The response is caused by cross-reacting allergens found in both pollen, and the fruits and vegetables.