Testing and Treatment

If you think your child has a food allergy, see your doctor, who may recommend a pediatric allergist. He'll likely perform one of two tests: the classic skin-prick, which entails scratching a small amount of the allergen into the skin and watching for a reaction, or a blood test that screens for allergy-related antibodies.

But know that allergy tests are far from perfect, says Hugh Sampson, M.D., director of the Jaffee Food Allergy Institute at Mount Sinai School of Medicine. It's possible to have an allergy that doesn't show up on a test, or for a test to show that your child is mildly allergic to a certain food even though he can eat it without a problem. Bottom line: Diagnostic tests are best used to help confirm a suspected allergy, rather than to go fishing for possible ones.

Another alternative for determining food allergies is simply to talk about your child's symptoms with your doctor. Dr. Sampson, for example, says he looks for common patterns. Does the child always develop symptoms within minutes of having a particular food? Is it a food known to provoke allergies? If the answers are yes, then you may be dealing with a food allergy.

Once you know your child is allergic to a food, the best thing to do is avoid it entirely. (Allergy shots, while often effective for respiratory allergies, aren't usually used to treat food allergies because there's a greater risk of a dangerous reaction.) If your child does accidentally eat the wrong thing, the best line of defense is to follow your doctor's emergency plan, which will likely include relieving symptoms with an antihistamine or an emergency shot of epinephrine, depending on how severe the symptoms are.

Several promising treatments are now being studied. Most involve "immunizing" a person against the food allergen by injecting a modified version of it together with a substance that tells the immune system to "back off," or treat it as harmless. If these treatments pan out, they may become available as soon as 2010.

Avoiding Allergens

Steering clear of allergenic foods can be one of the toughest jobs a mom can take on. Fortunately, as of January 2006, the Food and Drug Administration requires all food labels to state if ingredients include any protein derived from one of the [XREF "1696431" "eight major allergenic foods"]. But you still need to be vigilant about reading the fine print on labels, which can contain surprises.

"Who would ever have thought that baby-food meats would have dairy in them?" says Jennie Oko of Westmont, Illinois, who has became an ingredient detective ever since her son Matthew, 3, was diagnosed with a dairy allergy as a baby.