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Dear Dr. Lanny:
My 3-year-old daughter has tested positive for a soy allergy. We had been trying to figure out why she seemed to have so much indigestion so often. I’m told we’re lucky: The allergy could be much more severe. Her pediatrician said we need to eliminate from her diet all foods with soy in them, for a year, and then we’ll test again after that. Did you know that soy and soy derivatives are in practically every processed food there is? Can you suggest ways we can cope? Is my daughter likely to outgrow this allergy? (I hope so!)
A: I’m sorry that your daughter is having indigestion, and, yes, I did know that soy is in a host of different products. As a matter of fact I just checked the cupboard and found soy in one form or another in our white clam sauce, salad dressing, organic minestrone soup, and Iron Chef’s General Tso’s glaze. I would in turn ask you in what manner did your daughter test positive for soy allergy?
Although food allergy is not rare, neither is it as common as many people think. An estimated 3 percent of children and 1 percent of adults have some sort of food allergy. Although almost any food can be a concern, some 90 percent of allergy comes from eight groups: milk, soy, wheat, tree nuts, peanuts, egg, fish and shellfish.
Tree nuts represent many different varieties, a few examples being cashews, walnuts, pecans and hazelnuts. This obviously means that for the truly nut-allergic, pesto is out and Chinese food may be very risky. Peanut oil, interestingly, does not have peanut protein and can usually be eaten without problem.
Allergy is a reaction by the body’s immune system to a foreign protein. This type of immune reaction must be differentiated from food intolerance. True allergy is to the protein in foods and can cause unpleasant reactions, such as abdominal discomfort or itching, or life-threatening reactions such as complete collapse or inability to breathe. It is estimated that some 100 to 200 Americans die each year from food allergy. Even miniscule amounts of the food can cause major symptoms. Children may outgrow egg, wheat, soy and milk allergy, but usually remain allergic to fish or nuts.
Food intolerance, such as lactose intolerance, is not an immune reaction, and is dependent on how much you ingest. It is not life threatening. Many people can happily eat a small bowl of ice cream, but realize that a triple thick shake or a banana split will result in bloating, gas and personal embarrassment.
In the first paragraph I wondered how your child was diagnosed with soy allergy. I’d like to return to that question. Diagnosis of food allergy is notoriously difficult and requires great care not to over-diagnose. For young children, many doctors are hesitant to do scratch (also called prick) tests as little ones do not usually put up with multiple scratches.
Your doctor may choose to do a RAST test, which uses a small amount of blood to check for the body’s reaction to a number of possible allergens. They can be ordered specifically (e.g. cat dander), or more typically as a group of tests (e.g. food allergy panel or regional allergy panel). These panels are quite pricey, costing approximately $200 each.
Results are reported as different classes, the more concerning the higher the class. Even with an elevated class, however, a person may have eaten the particular food being tested with no reaction whatsoever. Consequently, the medical practitioner and the family have to take any positive results with a grain of soy (just a little humor) and definitely with a careful dietary and symptom history. In other words, don’t simply treat a lab test. Scratch tests and cautious challenges with the suspect foods can further clarify the situation.
There’s a question that often comes up regarding food allergy: Can a pregnant woman’s diet cause allergy in her child? The answer is simple…nobody is sure! It seems reasonable to recommend avoiding tree nuts and peanuts in the latter stages of pregnancy if you or a close family member has a strong history of severe food allergies. Until food allergy questions are more completely answered, this seems a small hardship for a possibly big payoff. To no great surprise, exclusive breastfeeding for the first months of life is probably beneficial.
So, what to do if your child has food allergy? If you can clearly associate a particular food with a reaction (e.g. hives soon after eating shrimp), then avoidance is the chief strategy. Reactions to offending foods are unpredictable but are not necessarily worse with successive encounters. If your child has had any respiratory or cardiac symptoms with food allergy, has significant asthma, or has a close family member with history of severe food allergy, then carrying an Epipen is wise and prudent. An Epipen is a small and very simple device to administer epinephrine, a potentially life-saving medication, in cases of severe reaction. A similar device, called a Twinject, carries two doses of epinephrine; it’s good to have available if you are not near medical care. The old standby, Benadryl (diphenhydramine), taken orally, is useful in mild reactions.
Food allergy is still fraught with uncertainties, and research to answer the questions is ongoing. Although fatalities can occur, and allergens are distributed in products you might not have suspected, most allergic reactions are modest and not life threatening. Breastfeed early in life, don’t be in a rush to add solids to children’s diets, and try to eat real food rather than processed stuff.
Read labels. If you can’t pronounce the ingredients, it’s not food, it’s chemistry. Food prices, like gas, are going crazy, so stay within your budget, but try to shop for fresh, organic and locally grown items.
Dr. Alan Freshman, father of two grown boys, practices at Syracuse Pediatrics. Consult your own physician before making decisions about your family’s health care. Send e-mail to him at firstname.lastname@example.org.