Bon Appetit: What You Need to Know About Food Allergies
Did You Know?
During the summer months, physicians encounter cases of "mango poisoning," a form of contact dermatitis that appears 48 hours after contact with the skin of a mango. Interestingly, people who are sensitive to poison ivy have an increased risk of developing a skin reaction to mango skin and cashews, yet are not more likely than anyone else to have a food allergy to these foods.
Did You Know?
People who suffer abdominal pain and diarrhea after drinking milk are not allergic to dairy products. They are in fact lactose-intolerant, which means their bodies lack an enzyme needed for the digestion of milk.
May 2001 — Food allergies are common, but did you know that 80 percent develop within the first year of life? Sensitivity to eggs, wheat and milk tends to decrease over time, but an allergy to tree nuts, peanuts, fish or shellfish is likely to be life-long.
Nevertheless, a food allergy can develop at any point in life and disappear just as suddenly. We asked Dr. Dana Wallace, a Pediatric and Adult Allergist at Memorial Regional Hospital and Chief of Medicine at Joe DiMaggio Children's Hospital, to share some insights into food allergies. As chairman of the drug and anaphylaxis committee for the American College of Asthma, Allergy and Immunology, she is uniquely qualified to tell us what we need to know.
"Eighty percent of children who are allergic react to only one or two foods. A true allergic reaction occurs within one or two hours-usually within a few minutes. Symptoms may include rash, itching, nasal symptoms, swelling, hives, difficulty breathing, eczema, intestinal symptoms or shock," says Dr. Wallace.
People with food allergies should carry small, pen-shaped vials of adrenaline (epinephrine) called Epi-Pens at all times, along with an antihistamine. An allergic reaction is an emergency, and it's better to be safe than sorry. If you start to develop an allergic reaction, administer the Epi-Pen, take the antihistamine to control itching, and go to the Emergency Room. For a serious reaction, it's wiser to call 911. "Remember that an antihistamine is not a substitute for adrenaline," Dr. Wallace warns. "Also, oral or injectable steroids can prevent a delayed reaction that can occur four to six hours later. They are not intended to treat an immediate reaction, as they usually take several hours to start working."
Don't Ignore the Warning Signs
Oral food allergy syndrome is usually less serious, that is, unless the patient ignores the warning signals. Apples, peaches, celery and carrots are common oral allergens, along with certain pollens that all contain common nucleic acid proteins. People with this syndrome feel their mouth itch when they touch their tongue to the offending food. Some patients experience swelling of the lips and throat, or go into shock. Sometimes, they may eat a small amount of the food before the reaction occurs.
Treatment may not be necessary in mild cases, but ignoring the itch can have consequences. "A friend with an oral allergy to peaches ate several pieces of homemade peach cobbler and ended up in the Emergency Room," says Dr. Wallace.
It's not always necessary to eat a food in order to have a reaction to it. For some people, simply breathing the vapors can cause a severe reaction. The problem is particularly acute in environments where escape is impossible, such as airplanes, where a high sensitivity to peanuts can be problematic.
Related Allergies
Surprisingly, people who choose an airline based on whether or not they serve peanuts may be able to down a bag of cashews with no problem. "Tree nuts (cashews, almonds, walnuts, pecans and the like) are not related to peanuts," says Dr. Wallace. "It's a common misperception."
Other foods and plants are related - for example, plums and apples, cantaloupe and ragweed. If you are allergic to one, you are likely to be allergic to the other. Birch pollen cross-reacts with carrots, apples, celery and hazelnuts. A food allergy skin test will tell you if you need to avoid a group of related foods.
While it is impossible to desensitize yourself to a food, cooking a fruit normally breaks down the allergen. However, both tree nuts and peanuts remain unchanged by the cooking process.
Read the Fine Print
While it might be wisest to avoid an offending food, misleading labels pose a serious health risk. The Food and Drug Administration has strict regulations about listing the contents of packaged or processed foods. But this practice does not always protect consumers who don't read the fine print.
"One of my patients who was highly allergic to peanuts reacted to a cookie made with almond paste. The baker swore it contained no peanuts. I asked him to get the can of almond paste and look at the ingredients. The list showed it contained no almonds, only peanuts. It was misleadingly labeled," Dr. Wallace remembers.
If you have a severe food allergy, Dr. Wallace suggests you check out the Food Allergy & Anaphyllaxis Network website at www.foodallergy.org. In addition to offering answers to frequently asked questions, this nonprofit organization provides warnings about misleading labeling and manufacturing processes, special allergy alerts, and links to other valuable websites. The information could save your life.