I’ve asked Dr. Farshchian to help us distinguish between food allergies and sensitivities and to help us better understand testing methods for each. While we’re not sure if food is the root cause of eczema, most of us have experienced first hand how food can trigger flare ups. I hope today’s post can shed some light on the IgE vs. IgG debate – knowing both can trigger eczema and asthma.
Eczema & Asthma – Testing for Food Triggers
By Dr. Thalia Farshchian, N.D. (Bio below)
Food sensitivity testing is gaining popularity to assist in identifying triggers to chronic conditions like eczema, asthma, nasal congestion and more. To draw a conclusion that a particular food triggers symptoms, the gold standard for identification is an elimination challenge.
The elimination challenge can be quite the challenge in and of itself when you are considering eliminating all of the most common triggers: gluten, dairy, eggs, corn, soy, nuts. In clinical practice, I have found food sensitivity testing to be a very helpful guide as it alleviates an element of stress on the child and family.
Understanding Food Reactions: Allergy (IgE) vs. Sensitivity (IgG)
There are two primary types of antibody reactions to food: IgE immediate response and IgG delayed response. With immediate IgE allergic reactions, you will notice symptoms right away and they can be life-threatening. For example, a person eats peanuts and they break out in hives or experience tightness in their throat and difficulty breathing. It is usually simple to make the correlation between the offending food and an immediate symptom.
Delayed IgG food sensitivity reactions are not as straight-forward and are addressed differently. With this type of a sensitivity you could eat a trigger food on Monday, but not experience symptoms for up to three days. This makes it very difficult to discern which food is causing your symptoms. These reactions are not life-threatening, but can significantly affect quality of life and development of chronic disease, such as eczema and asthma. Types of reactions range from headaches to bloating to skin conditions and more.
I just learned about food sensitivity testing! #eczema #asthma #foodsensitivities @eczemacompany
Immediate reactions are most commonly tested by an allergy specialist using the skin prick test. This test exposes a person’s skin to a solution containing a potential allergen and then needle pricking the skin to allow the solution to penetrate. If the skin develops a red, raised itchy area in reaction to a skin prick, the patient is considered to have a positive allergic reaction to that substance. The skin prick test is fairly reliable in detecting IgE reactions to environmental allergens, but less so with food.
Allergies can also be tested via an IgE antibody blood test to potential allergens. As with any kind of blood testing, recent exposure is helpful in identifying potential allergens.
To test food sensitivities, the easiest way is with a food panel via blood test. This test is usually ordered by alternative healthcare providers and typically not done by your conventional doctor. The E95 Basic Food Panel by Meridian Valley Labs I, offered at Discover Health, is unique because it tests for IgE and IgG antibodies together via blood test and includes at least 95 of the most common foods. Though there are many companies that do IgG testing, I find Meridian Valley’s to be quite consistent with the clinical results after the elimination. I have now used the same test for over 5 years.
The test can be done on infants and young children easily without a blood draw. On our children, we use a finger prick blood sample similar to what a diabetic would use to check blood sugar levels. Children still do not love it, but it does avoid the trauma of a full blood draw. I typically get very good clinical results with this method, but testing this way can only identify IgG (delayed) sensitivities and not the combo of IgG and IgE antibodies.
With any kind of allergy or sensitivity testing, false negatives or positives are common. The tests merely act as a guide in treatment and the gold standard is eliminating exposure to the potential allergens to see if symptoms resolve.
For additional testing options, check out this post: Which Food Test is Right For You?
Once you have completed testing, you would proceed to a guided elimination challenge. The challenge involves eliminating the food or foods you reacted highly to for 4-6 weeks.
After that elimination period, you systematically reintroduce the foods back into your diet one at a time under a practitioners care, especially when there is a concern of a severe allergic reaction. Leave a few days break between trying each food to clearly distinguish reactions. During your reintroduction, keep a diary of the changes you experience. At the end of the day, the proof is in the pudding. If you notice your symptoms (hives, itching, swelling, more severe) return immediately, you are very likely allergic to that particular food. If your symptoms (headaches, bloating, lack of energy) take a few days to return, you are likely sensitive to that particular food.
Once you have the information, you can make an informed decision of whether eating a particular food is worth the cost.
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Bio: Dr. Thalia Farshchian is a naturopathic doctor who has been featured on ABC News, FitLife.tv, The Marina Times, Nob Hill Gazette, various blogs and sits on the medical advisory board for quickly emerging health and wellness companies like The Honest Company. She is a highly sought after expert on hot topics like hormone disorders, inflammation, chronic disease prevention, anti-aging, food sensitivities, and weight loss.
Her mission is to empower people to make simple changes to their diet and lifestyle that greatly impact the health of themselves, their family and environment. You can follow Dr. Thalia on Facebook, Pinterest and Twitter where she regularly posts her medical insights and the latest findings in healthy living.