Food Allergies: IgE and IGg*
IgE (immunoglobulin E):
Most of us recognize the following allergy symptoms: rash, hives, swelling, breathing difficulties, etc.
This type of allergy is caused by IgE (immunoglobulin E) in the body. This is the type of allergy that is being tested for in the common skin prick or scratch test.
IgG (immunoglobulin G):
The other type of allergy is less obvious, and the symptoms can appear many hours (even days) after exposure. This type of allergy (which can also be referred to as an intolerance) is usually caused by IgG (immunoglobulin G) in the body. IgG allergies have many different symptoms, and their symptoms can vary from person to person. Common symptoms include: nasal congestion, wheezing or asthma type symptoms, congestion in the ears often leading to recurrent ear infections, and eczema. In some children, IgG allergies can cause brain inflammation resulting in behavioural issues resembling ADHD and autism. Most allergists do NOT test for IgG allergies, and aren’t even aware of this type of allergy.
Testing for Allergies and Intolerances:
IgG testing and most allergists: Unfortunately most allergists do not think outside the box – if it’s not something they can see physically, like on the skin prick test, then it can’t be related to allergies of any sort. In their mind, there’s just no possibility that IgG allergies can produce unseen effects on the body and brain. Also it’s such new and cutting-edge research that the information isn’t widely known or accepted yet. Allergists have been known to say, “everyone has IgG antibodies in their system…” Of course we all do! We all have IgE antibodies in our system, too. It’s not just the presence of them that counts, it’s the amount. If the level is within normal limits, then all is well. If it’s sky high, then that’s not normal and the body will have an allergic reation. Since IgG allergies produce delayed effects (could be 8 hours later, could be 3 days later) it’s hard to link the two. However, since IgE allergies produce immediate effects it is easy to see, test, and prove. Furthermore, the person being tested needs to have been recently exposed to the food in order for it to show up on an IgG test. So if a patient never, ever eats dairy, then dairy will likely not show up as an IgG allergy on the test because the body hasn’t had any reason to produce the IgG antibodies to it. This is not the same for IgE antibodies.
*Thank you to Sheri, for her posts!
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