Food allergies are a concern for many parents – especially those of younger children who are being introduced to new foods on a regular basis. But it can be hard to determine what is a food allergy versus a food intolerance. Let’s test your knowledge: which of these scenarios represents a case of food allergy?
A. A 2–year old with severe eczema that periodically flares up. The mother blames food for the flare-ups but can't figure out which ones.
B. A 3–year old who consistently develops generalized hives, wheezing and then vomits shortly after eating peanut butter.
The answer is B! This is an example of a peanut allergy.
Over the past 20 years, the prevalence of food allergies in children has increased. The reason why is unknown, but any food can cause a food allergy. The most common food allergies are caused by milk, eggs, peanuts and tree nuts - some of which can be outgrown.
So, what is a food allergy?
Food allergy is a reaction that occurs following ingestion of a food. The generalized hives, wheezing and vomiting presented in scenario B are all symptoms of a food allergy. Other symptoms may also include trouble breathing, low oxygen causing confusion, restlessness and rapid heartbeat; a pounding feeling in your head or chest.
Parents may be quick to think any unwanted symptom without an obvious cause is related to food allergies. This is not true. A parent who suspects that an "unknown" or "hidden" food is the cause of their child’s symptoms likely does not find their child has a food allergy. Patients with a food allergy generally will know what specific food they ate that caused a specific reaction.
Testing for food allergy
The goal of testing is to determine if the food is safe for the patient to eat. A patient who can eat a specific food without a reaction is not allergic to that food and does not need a test. Food allergy testing should be discussed (or performed under) the guidance of an Allergist/Immunologist. Tests are performed to confirm the diagnosis and how to monitor the disease activity.
False positive food tests are common and should be performed only for foods suspected to have caused a reaction. Food panels (unless defined ones for nuts, shellfish, and fish) should be avoided.
Treatment for food allergy
Patients who are at an increased risk of anaphylaxis should avoid the food entirely and be given an epinephrine autoinjector – commonly known as an epi-pen. Instructions on how to use an epi-pen, along with proper training, is necessary for a child’s anaphylaxis action plan.
Remember: the treatment for anaphylaxis is epinephrine. Antihistamines will treat mild symptoms only, but they do not treat anaphylaxis.
For patients diagnosed with a peanut allergy, the Food Allergy Center at Children’s Mercy Kansas City currently offers peanut oral immunotherapy (OIT). This treatment provides desensitization but is not a cure for peanut allergy. Patients treated with OIT are at lower risk of peanut-induced anaphylaxis, but still need to avoid peanuts and carry epinephrine.
What about early introduction?
Early introduction of peanuts to children between 5 and 11 months of age reduces their risk of developing an allergy. Children at high risk of developing food allergies should be fed age-appropriate forms of peanuts at least several days per week. Similar methods could also be practiced for eggs and dairy. To parents that might be anxious about early introduction, the Children's Mercy allergy clinic routinely provides early introduction of peanuts.