Allergies are a common occurrence and present a complex web of immune responses that can baffle even the most seasoned medical professionals. Traditionally, allergists have used the prick test and measurement of immunoglobulin E (IgE) levels in the bloodstream to identify allergens. Today, however, the landscape of allergic reactions is evolving, shedding light on the need to expand traditional testing methods.
Allergists employ two primary types of tests to assess allergic responses: the Total IgE test and the Specific IgE test. The Total IgE test measures the total IgE concentration in the blood, providing a broad assessment of allergic potential. The Specific IgE test delves deeper, gauging the presence of IgE antibodies in response to specific allergens. Manifestations of IgE-mediated allergies encompass a broad spectrum of symptoms, including allergic rhinitis (hay fever), anaphylaxis and contact dermatitis. When you think of common food allergies such as shellfish, tree nuts or eggs, this is typically the type of allergy being referenced — IgE allergies. These reactions are pretty easy to spot. Most people notice if they break out in hives after a handful of peanuts.
However, a significant percentage — ranging from 50 percent to 60 percent — of allergy blood tests yield false-positive results, according to a Cleveland Clinic report from February 2022. A false positive might stem from the test registering incompletely digested food proteins as allergens. Alternatively, the test might identify proteins similar to the allergenic food protein as the allergen itself, even when the foods are in fact different. For instance, in the case of an individual with an IgE allergy to peanuts, the IgE test could yield a false-positive result for other members of the legume family, like green peas, due to their significant protein similarity. This reality underscores the complexity of identifying precise allergenic triggers.
Beyond IgE Testing
Consider the scenario where conventional IgE allergy tests return negative results, yet classic allergy symptoms persist. Clearly, the immune system is reacting to some kind of stimuli.
It’s possible that another class of antibodies, distinct from IgE, is at play. Notably, inflammatory responses mediated by IgA, IgG4, and IgM antibodies can provoke adverse reactions to certain foods. Conventional tests fail to detect these antibody elevations, potentially missing sensitivities and inflammation triggers.
To add an additional layer of complexity, IgA and IgG food reactions can materialize hours or even days after exposure. This delayed response obscures the process of pinpointing triggers through symptom tracking alone. So the eggs you had yesterday can trigger the migraine you have tomorrow. Or your skin rash is the result of eating dairy products four days in a row, which is too much of a load for your immune system, whereas you could have gotten away with eating it two or three days straight.
The good news is, these antibodies can be tested. You don’t have to rely on symptom tracking alone.
Could it be Histamine Intolerance?
Histamine intolerance introduces yet another facet to the landscape of immune reactions. Unlike allergies, histamine intolerance isn’t tied to an increase in IgE antibodies or a specific food sensitivity. Rather, it stems from an excess of circulating histamines which yield allergy-like symptoms. There can be several reasons for excess histamines: excessive histamine production, insufficient levels of the histamine-degrading enzyme DAO, overconsumption of histamine-rich foods, alcohol consumption and certain medications.
As functional nutritionists equipped with a holistic perspective, we have devised a straightforward experiment to test potential histamine intolerance in clients. First, we eliminate high-histamine foods from the diet. In tandem, we enhance the action of the DAO enzyme through supplementation. Clients grappling with histamine intolerance often experience rapid symptom improvement as a result of this two-pronged intervention.
It’s important to underscore that histamine-intolerant individuals aren’t allergic to high-histamine foods, per se. Instead, these foods overload the body with histamines and create allergy-like symptoms.
As medical understanding evolves, so too does our ability to unravel the complexities of the immune system and devise targeted interventions.