IgG Allergies in Autism, ADHD, Asthma, Autoimmune and More

by Kelly Dorfman, MS, LN


IgG Allergies in Autism, ADHD, Asthma, Autoimmune and MoreIntolerance to certain foods, especially gluten (wheat related grains) and casein (milk protein), is a common occurrence among children with developmental delays.

Before adopting an elimination diet, however, many parents consult an allergist to determine if the diet is necessary. Surprisingly, after extensive scratch testing, the child is often found not to be allergic to any foods.

Some parents choose to eliminate gluten and casein proteins anyway, and find their youngster responds with improved attention, sleep and/or language skills.

How is this improvement possible if the child was not allergic in the first place? The answer lies in understanding the difference between allergies and other types of chemical reactions within the body.

IgE versus IgG Reactions

Allergies are defined as specific reactions within the immune system involving an antibody called immunoglobulin E (IgE). Immediate responses such as hives, congestion or swelling typically result from IgE activity. Traditional scratch testing identifies IgE triggers such as pollen or peanuts, which can cause symptoms that range from annoying to lethal.

Very different responses are delayed allergy reactions. If they occur more than two hours after eating a food, they may result from immunoglobulin G (IgG), rather than IgE activity. IgG reactions may cause symptoms such as sleep disturbance, subsequent bed wetting, sinus and ear infections, or crankiness.

Blood tests rather than scratch tests are the only way to screen for IgG allergies. If your doctor correctly states that IgG testing is not reliable, say you are aware of that fact, but are interested in the results anyway. The testing may provide information about what foods may be bothering your child’s immune system.

Where immunoglobulins are involved, the word “allergy” can legitimately be used to describe symptoms after exposure. A reaction to gluten or casein sometimes shows up in IgG or IgA blood testing and is, therefore, referred to as an “allergy.” This conclusion can be misleading, because the more likely reason for casein and gluten intolerance is poor digestion.

Poor Digestive Function

Poor digestive function has a number of causes. It may result from an immature gut in infants and fr_om heavy antibiotic usage or the lack of the protein digesting enzyme DPP4. The possible relationship between the lack of DPP4 enzyme and the symptoms of PDD /autism is the recent discovery of Dr. Alan Friedman at Johnson & Johnson Labs. Without essential digestive enzymes, such as DPP4, partially digested proteins such as gluten and casein may leak into the blood.

Partially digested proteins have odd configurations and mimic other complex molecules such as endorphins. Endorphins are nervous system proteins that act as painkillers. Partially digested gluten or casein proteins may bind to pain killing (opiate) receptors and cause behavioral symptoms of poor eye contact, irritability or disconnection.

Poor digestion may or may not elicit an immunoglobulin response. It may cause inflammation symptoms instead, such as intestinal irritability, stomachache and/or diarrhea. These reactions are not technically allergies. Nor is opiate activation technically a true allergy. When IgG or IgE testing finds milk or gluten sensitivity, it is because the chemical messages weaving through the body tripped the allergy system.

Other Gut Problems

Similarly, when reactions to a food are aggression, poor concentration, or seizures, many other explanations are possible. All body systems are interdependent and so intertwined that designing tests to understand and study their discrete functions can be very difficult. The artificial distinctions placed between immune and neurological systems hinder diagnosis and treatment.

This imprecise diagnosis can be very frustrating, but there are too many ways for the body to react and communi­cate. That is, it is unlikely that one testing system will ever be able to find and sort all possible reactions.

Best “Test” for Reactions

The best “test” for reactions is elimination of suspect items. The limitation with this approach is that irritants can interact. That is, exposure to one item will not cause symptoms, but when two mildly reacting foods are present, together they trip a response by overloading the system.

In “load”reactions, a little is tolerable, but too much of one or a combination of two or more causes trouble. Blood testing may then be useful, but the problem in load allergies is usually a leaking gut.

Rather than eliminating additional foods, the answer is repairing the underlying leak. The reason that secretin has been extremely useful in autism is its ability to correct gut function.

For more information about IgE and IgG reactions and the leaky gut, read Biological Treatments for Autism and PDD and The Leaky Gut Syndrome.