IgE-Mediated Food Allergies

• IgE-mediated food allergies typically develop in the first or second year of life, after a child begins to ingest table food. 
• IgE-mediated allergies are triggered when the immune system recognizes a protein as an enemy and releases an onslaught of inflammatory triggers called histamines, causing the allergic symptoms.
• A child is two and a half times more likely to develop a food allergy if a sibling or a parent has a known food allergy.
• Food allergies affect about five percent of kids under the age of five and about four percent of all teenagers.
   

Foods that cause IgE-mediated allergies in children include:

• milk
• eggs, in particular the egg whites
• peanuts
• tree nuts like cashews, almonds, walnuts, pecans, etc., (remove comma)
• wheat
• soy
• fish
• shellfish
   

Symptoms of food allergies in kids

Not all reactions that occur after eating foods are an allergy. For example, children can have loose stools or a burst of energy when they eat too much sugar, or gassiness or bloating if they have a milk sensitivity.

A true allergic reaction to foods in IgE-mediated allergies can be dangerous.  Symptoms of food allergy develop quickly after eating or drinking the allergic food.  Symptoms usually appear within a few minutes to two hours.

• Children can develop redness, raised itchy welts (hives), swelling and substantial itching.
• If the respiratory system is affected, children can have breathing problems.
• Even sneezing or a clear runny nose can be a sign of food allergy, as can throat tightness due to swelling of the lips, tongue or airway.
• When the gastrointestinal system is involved, symptoms can include nausea, vomiting, and/or diarrhea.
• If the circulatory system is involved, symptoms can include paleness, flushing, and a feeling of light-headedness or a weak pulse.
• Older children may show food allergy symptoms by feeling anxious or agitated and, in worse case scenarios, they can even lose consciousness.
• Anaphylaxis is a severe, potentially life-threatening allergic reaction that can occur within seconds or minutes of exposure to an allergen.  Patients usually have symptoms that involve more than one body system. For example, children who develop swelling of the lips and shortness of breath with light headedness would have more than two body systems involved and anaphylaxis should be suspected.  If these symptoms are not recognized quickly and treated immediately, then children can progress to developing low blood pressure, blockage of breathing airways or even death.

For this reason, it is very important that parents, teachers, child care providers, school nurses, summer camp leaders and even parents of a child’s friend be educated and readily able to recognize symptoms and administer the appropriate treatment to prevent anaphylaxis or death.

Preventing food allergies

Research shows there are ways to minimize future risks for developing food allergies. Breastfeeding for the first four to six months of life may help to prevent the development of food allergies. In addition, research strongly suggests that early introduction of allergenic foods can reduce the risk of future food allergies. It is recommended that peanut butter be introduced to all infants between four and six months of age, and eggs should be introduced as soon as the child is able to eat soft table foods.  Ongoing research continues to provide information towards food allergy prevention.  Lastly, some food allergies can be outgrown over time.

In general, parents notice early in their child’s life when abnormal symptoms of the skin, intestinal or circulatory system develop after eating a particular food. These concerns should be discussed with the pediatrician. If the doctor feels like these symptoms are suggestive of a food allergy, he or she may decide to refer the child to a pediatric allergist. The benefit of seeing a specialist is that appropriate tests can be performed to confirm a food allergy and regular follow-up with an allergist helps provide education and support to families. An allergist at St. Louis Children’s Hospital can assist families with long term goals and food allergy testing.

Dr. Lori Buffa is a pediatric physician with Cloverleaf Pediatrics located near the Barnes-Jewish St. Peters Hospital campus. You can schedule an appointment with Dr. Buffa by calling 636.928.WELL.