IgE-Mediated Food Allergies

Also known as: food allergies.

What are IgE-Mediated Food Allergies?

IgE is short for immunoglobulin E, an antibody that is part of the body’s immune system (the system that protects the body from invading bacteria/viruses and other foreign material) present in the bloodstream. IgE type of food allergy refers to a specific type of abnormal immediate-type hypersensitivity immune inflammatory reaction, usually to a protein in a food.

What causes IgE-mediated food allergies?

The cause of IgE allergy is very complex, in brief, the body recognizes a protein in food as foreign and produces IgE to combat it. The IgE produced sits on a cell which on next exposure to the protein causes the cell to breakup and release chemicals (such as histamine) which cause the signs/symptoms seen. Both genetic and environmental factors appear important.

For example a family history of allergy, or the way food is processed (roasted peanuts cause more problems in allergic children than raw or boiled peanuts) both increase the likelihood of food allergy.

90% of food allergies in children are caused by cow's milk, egg, peanuts, tree nuts, fish, shellfish, soy and wheat. Any food can cause food allergy and a third of children will have symptoms on their first known exposure to the food (they may have been previously exposed for example through the skin).

What are the symptoms of IgE-mediated food allergies?

Symptoms generally occur within 30 minutes of ingestion (they can start up to 2 hours later), and are usually mild.

Common mild to moderate signs/symptoms include one or more of hives, red and itchy eyes, a runny or congested nose, wheezing, vomiting and diarrhea. In some cases, the symptoms can be severe (anaphylaxis, a severe whole body reaction) and include trouble breathing, throat swelling, tongue swelling, weak pulse, trouble swallowing and loss of consciousness.

What are IgE-mediated food allergies care options?

Mild IgE-mediated food allergic symptoms can often be treated with antihistamine medications. If symptoms worsen (which can happen rapidly), or if more than one part of the body is involved, epinephrine (Epi-Pen which should always be carried if a child has food allergies) should be given immediately and Emergency care (call 911) notified.

Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: May 06, 2021 09:30 AM

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