Pediatric food allergies

What are pediatric food allergies?

A food allergy occurs when a child’s immune system mistakenly attacks a food protein. Food allergies can be serious medical conditions. They affect up to 15 million people in the United States, including one in 13 children.

During an allergic reaction, the immune system produces abnormally large amounts of an antibody called immunoglobulin E — IgE for short – and antibodies fight the food allergens by releasing histamine and other chemicals, triggering symptoms.

The most common food allergens are the proteins in cow’s milk, eggs, peanuts, wheat, soy, fish, shellfish and tree nuts. In some food groups, an allergy to one member of a food family may result in allergies to other members of the same group. This is known as cross-reactivity.

The most severe allergic reactions are often associated with peanuts, tree nuts and shellfish.

Food allergies are increasing among children, and there are several hypotheses as to why, though none have been proven:

• The hygiene hypothesis - Developed lifestyles with decreased exposure to bacteria may disrupt the normal development of the immune system.
• Delayed introduction of allergenic foods - Studies have indicated that introduction of some foods, like peanut, into the diet early in life before allergy has developed, may decrease the risk of developing an allergy to that particular food.
• Forms of food - Different forms of the same food – roasting vs. boiling vs. baking, for example – can provoke different reactions (or no reactions) from known allergic people.
• Increased awareness and reporting

What are the signs and symptoms of pediatric food allergies?

Symptoms of a food allergy usually appear within minutes to hours of consuming an allergen.

Mild food allergy symptoms include:

• Hives (reddish, itchy areas on the skin)
• Eczema (a dry, itchy rash), itchy mouth or throat
• Nausea
• Diarrhea
• Dry cough
• Swelling around the eyes or on the face

Severe symptoms may include one or more of the following:

• Obstructive swelling of the throat, tongue or lips
• Trouble breathing or swallowing
• Wheezing
• A drop in blood pressure causing fainting or weakness
• Chest pain
• A weak pulse
• Loss of consciousness
• Anaphylaxis - A severe, and potentially fatal, allergic reaction. Someone suffering from anaphylaxis usually has symptoms that involve the skin, nose, mouth, or gastrointestinal tract as well as difficulty breathing or reduced blood pressure (leading to paleness, confusion, loss of consciousness). 
  • Anaphylaxis must be treated immediately with epinephrine (adrenaline), a shot that reverses severe symptoms.
  • The anaphylaxis sufferer should then be taken to the emergency room.

How are pediatric food allergies diagnosed?

Your child’s doctor will ask detailed questions about allergy symptoms and history. The doctor may consider ordering a blood test and/or perform skin prick food allergy tests, which indicate whether food-specific IgE antibodies are present in your child’s body.

• Skin prick tests can usually be administered in a doctor’s office and provide results within 15 to 30 minutes. A nurse or doctor will prick your child’s skin with a sterile lancet that contains a tiny amount of food allergen. The tests are considered positive if a bump develops at the site.
• Blood tests - If your doctor orders blood tests, your child will have blood drawn at a lab and results will be available in about a week.

Based on the results of these tests and reported symptoms, your child’s doctor will determine if your child is likely to be allergic to the food or is likely to be able to tolerate the food without having an allergic reaction.

• Oral food challange - If it remains unclear whether your child is allergic or tolerant to the food in question, your doctor may recommend an oral food challenge. In this procedure, your child is fed a serving of the food in question under strict supervision in the Food Allergy Center so that if a reaction does occur it may be recognized promptly and treated appropriately.

How are pediatric food allergies treated?

If your child is allergic to a food, they must avoid the allergenic food, and both children and caregivers should be educated on how to avoid these foods and how to administer epinephrine in the case of accidental exposure.

Some children outgrow, or have less severe reactions with, allergies to eggs or cow’s milk, but peanut, tree nut, fish, and shellfish allergies seem to be long-lasting.

Because serious, or even fatal, reactions may occur outside the home, you – as a parent or caregiver – must ensure your child’s school, coaches, babysitters, friends’ parents, chaperones on field trips and others have written knowledge of the allergy, emergency plans and access to epinephrine.

You may meet with a registered dietitian to discuss avoidance and nutritional supplementation for your child.