Has your child experienced an adverse reaction after eating, causing you to wonder if she has food allergies? Recent surveys show that as many as 25 percent of American households have made major overhauls to the foods they eat due to a belief that someone in the family has food allergies.

Thankfully, scientific studies suggest a much lower number of people with actual food allergies – only about 6 percent to 8 percent of children (and 2 percent of adults).

This data shows that many people mistake any bad reaction to food as a food allergy. But there is an important difference between food intolerances and food allergies.

Food intolerances vs. food allergy

Food intolerances occur when the body has an abnormal reaction involving a food. The majority of these reactions occur due to the quality of the food itself. Eating expired fish or shellfish, for example, can cause hives, itching, nausea, diarrhea and vomiting. While these symptoms look like allergic reactions, in this case they are not caused by an allergy.

Bacteria and viruses can cause food poisoning. Food poisoning may cause nausea, diarrhea and vomiting – which can be confused with symptoms of food allergies.

Other causes of food intolerances maybe due to your child’s biological makeup. Some children are naturally unable to tolerate milk. Lactose intolerance is quite common and may cause children to feel gassy, bloated and have diarrhea.

Another problem could be a condition such as Celiac disease which may cause your child to get sick from eating grains like wheat, rye and barley.

While not allergic, these reactions can affect your child’s quality of life and should be managed with help from her physician.

So what is a food allergy? As allergists, we consider food allergy in general to be a reaction that occurs when the body’s immune system mistakes harmless proteins in food as a threat to health. When the immune system goes on attack, as it would with a virus, chemicals released can lead to allergic reactions.

The majority of food allergies in childhood involve one of eight foods:

  • Milk
  • Egg
  • Peanut
  • Wheat
  • Tree nut
  • Soy
  • Fish
  • Shellfish

Fortunately, many food allergies such as milk and egg are outgrown by a child's fifth birthday. However, peanut, tree nut, fish and shellfish tend to be life-long. These foods are also commonly associated with more severe allergic reactions.

Symptoms – mild and severe

Most food allergies will occur immediately within minutes to a couple of hours. Skin is the most common organ involved and may include mild itching or hives. At times, some allergic reactions to foods can be severe and even life-threatening. Severe allergic reactions are called anaphylaxis. The prompt administration of epinephrine may be life-saving in an anaphylaxis.

The most common, worrisome allergic symptoms may include:

  • Localized symptoms: Itching or swelling of the lips, tongue and throat
  • Skin symptoms: Swelling and hives across the body
  • Respiratory symptoms: Wheezing, chest tightness or asthma attack
  • Neurological symptoms: Dizziness, confusion, weakness, feeling faint
  • Gastrointestinal symptoms: Vomiting, abdominal cramping, diarrhea
  • Cardiovascular symptoms: Drop in blood pressure, rapid heart rate, loss of consciousness


Your child’s allergist will collect a detailed history and conduct a physical exam which is essential for diagnosis of food allergies. An important part of diagnosis will involve testing for foods. Food testing may involve a blood test or a skin test.

Allergy skin testing is the most accurate test and can best determine which foods your child is allergic to. A tiny amount of suspected foods will be scratched, or pricked, on the surface of your child’s skin. If your child is allergic, small red bumps will appear at the site of the food. This test is safe, comfortable and fast – results are available in about 15 minutes.


In mild cases of food allergies, treatment with antihistamines may be enough. However, when worrisome signs or symptoms occur, an allergic reaction must be treated quickly to prevent it from progressing to a more serious stage.

To effectively treat an allergic reaction, you and your child must be prepared. Have medications (epinephrine and antihistamine) at hand and know how and when to use them. When your child is old enough, teach them when to take medication, as well. Be sure teachers, coaches and other adults that supervise your child are aware of her food allergies and prepared to handle a reaction.

In serious reactions, an epinephrine auto-injector should be used immediately. The sooner the epinephrine is administered, the more effective it will be. Once epinephrine is administered, call 911. A serious reaction will need further treatment at the emergency room.

If your child is prescribed an epinephrine injector, read the instructions in the package immediately to learn how to use it. You can also ask your pharmacist for a demonstration unit or ask your doctor to do a demonstration for you. Make note of the expiration date and be sure to get a replacement.


Andrew S. Kim, MD, is an allergist/immunologist based in Fredericksburg, Virginia.

The American Academy of Allergy, Asthma & Immunology is the largest professional medical association devoted to the research and treatment of allergic disease. The AAAAI offers educational materials for patients online at www.aaaai.org.