The most important test of all is the medical history - Scott Sicherer
Diagnosing allergies can be difficult. A doctor will often go through several steps before making a diagnosis, including specialized tests, a comprehensive interview about your ailments, and a physical exam. But it can sometimes take several months to get a correct diagnosis. Much like a detective working on a case, your provider will need to work by collecting information from you and from the different tests they organize. Together, you may need to test a few different strategies, such as avoiding possible triggers and then reintroducing them. This process can be slow, frustrating, and anxiety provoking.
It’s no surprise, then, that many people are drawn to alternative allergy testing. Such tests can be a tempting way to get a quick answer about your allergies. But most alternative allergy tests do not have any science behind them. In other words: If a test sounds too good to be true, it probably is. And in general, these tests are more likely to do harm than good...
Some people without allergies may still be sensitive to foods. This is called a food intolerance. Food intolerance can cause some of the same symptoms as a food allergy. However, it is not caused by an immune system reaction...
There is no single test to diagnose allergies. So you should be suspicious of any test that claims to be capable of diagnosing your allergies all by itself. To diagnose allergies, doctors generally look for:
- A history of symptoms when you are exposed to a suspected allergen (e.g., your eyes itch every time you are around cats)
- A positive result on skin prick or blood test results
- A positive response to an allergen challenge test
What tests to avoid
There are many tests claiming to diagnose allergies. Some of them can be found online. Others are offered by special practitioners. But, unfortunately, there is no scientific evidence behind these tests. Professional allergy organizations like the Asthma and Allergy Foundation of America (AAFA) advise people not to use these tests...
IgG food intolerance test
What it is: This test looks for special molecules called IgG antibodies in your blood. In theory, the presence of these antibodies can show whether your immune system is sensitive (allergic) to certain foods.
The reality: IgG antibodies are also found in people without food allergies or intolerances. Having these antibodies does not mean you are sensitive to these foods. It just means your immune system has been exposed to them. Checking for these antibodies cannot diagnose a food allergy or a food intolerance.
Vega machine test
What it is: This electroacupuncture machine measures electrical resistance across your skin at various points. These measurements supposedly provide information about food and environmental allergies.
The reality: There is no scientific evidence that Vega measurements are related to allergies. Results are the same in people who do and do not have allergies. This test is not recommended for diagnosing allergies.
What it is: This test uses bioresonance technology to examine hair samples. In theory, certain patterns of electromagnetic resonance from a hair sample can tell you if you have food or environmental allergies.
The reality: There is no scientific evidence that hair is involved in allergic reactions.
What it is: In this test, a patient holds a suspected allergen in their hands or mouth. A practitioner then assesses muscle weakness. This practice is supposed to determine whether an allergy is present.
The reality: There is no scientific evidence that allergies cause muscle weaknesses. Results may be influenced by the practitioner. It is not a useful tool for diagnosing allergies.
Cytotoxic tests (ALCAT, FACT, Bryan’s test)
What it is: In this test, a blood sample is mixed with a suspected allergen. The white blood cells are then monitored for injury. In theory, cell injury demonstrates whether there is an allergy.
The reality: There is no scientific evidence to support this claim. The reaction of white blood cells is unchanged whether you do or do not have an allergy.
Nambudripad’s Allergy Elimination Techniques (NAET)
What it is: This is a system of diagnosing and treating allergies. The system is based on the belief that allergies are caused by an “energy blockade” and can be treated with acupuncture.
The reality: There are no published studies that say these techniques can identify and/or treat allergies.
What it is: In this test, a practitioner takes your pulse twice, once before you are exposed to an allergen and then again 15 minutes after exposure. In theory, your pulse will change if you are allergic to the substance.
The reality: There is no scientific evidence that there is a reliable connection between increased pulse and allergies.
What are the consequences of alternative allergy testing?
Unproven allergy testing can have serious consequences. These tests are often expensive and are usually not covered by health insurance. What’s more, they can lead to false hopes and expectations and even delay correct diagnosis and treatment.
Many people who use these tests may get an incorrect result. A wrong diagnosis can have a significant impact on your mental and physical health. It may also cause you to make unnecessary lifestyle changes, like not eating foods you enjoy. Believing you are allergic to certain substances can have a significant impact on your quality of life.
Source: Sarah Gupta MD & Sophie Vergnaud MD, The Truth About Fake Allergy Tests, GoodRx, June 8, 2020.
Skin tests, first developed almost a century ago, are still the mainstay of allergy testing. They are easy and safe to do, give fast results, and are relatively inexpensive, which makes them the best way to start looking for specific allergies.
Now, a new study sheds light on the effectiveness of a test called a food challenge to determine whether a person can tolerate a food they once reacted to.
Allergy skin testing is simple, quick, and easy to perform. It is low cost and has high sensitivity. All of this makes skin testing preferable to blood testing for the diagnosis of IgE mediated diseases. If a provider doesn’t offer skin testing, blood testing is considered an acceptable alternative to determine the appropriate therapy for the allergic patient. But given the choice, choose skin testing.
Blood testing helped these people discover the truth behind their symptoms
Allergy tests aren’t perfect. Often, test results are confusing or ambiguous. Sometimes a test might suggest you have an allergy to something that has never bothered you.
For all those reasons, allergy tests are most useful when you’ve worked with an allergist first to make an educated guess about your allergies. Once you have an idea of what allergy you might have, you can do the right tests to find out exactly what you need to know.
Food allergies can be scary. Here how to reduce your baby’s risk, understand allergy tests and respond to a reaction if it happens.
For parents of children with food allergies, this may be both welcome and unsettling news: Many kids whose allergies were diagnosed on the basis of blood or skin tests alone may not be truly allergic to those foods, experts say.
Detection of IgG antibodies has been discredited as a reliable diagnostic tool since the 1980s. Unlike IgE antibodies, which are responsible for allergies, IgG antibodies can be found in allergic and non-allergic people regardless of whether they are healthy or sick. IgG antibodies are the normal antibodies made by the body to fight off infections. Increase in levels of IgG antibodies present in the circulating blood is thought to be a normal response to the ingestion of food. In fact, IgG antibodies have actually been found to go up during successful research studies on food immunotherapy.
"The most important test of all is – can you guess what it is?" Sicherer asks. "The most important test of all is the medical history."
“In all my years of practice, I have never sent an immunoglobulin G test because they have no ability to predict food sensitivity,” he said.
That’s because immunoglobulin G stems from the body’s normal immune response to exposure to many substances, including food. High levels don’t indicate a problem; they simply point to foods a person recently has eaten. When a person sees the doctor to learn about possible food intolerances, they’ll likely be irked to find that the cash they spent on food sensitivity testing ordered online or at an “alternative” practitioner’s office was money down the drain.
“Most patients in the end, when we have done our workup and come up with a plan,” Hartz said, “are actually quite frustrated that they spent all this money on a useless test.”
Misdiagnoses leading to unnecessary treatments and poor diets, sometimes causing malnutrition, says Sense About Science.
The American Academy of Allergy, Asthma & Immunology (AAAAI) does not recognize the validity of IgG tests in diagnosing food sensitivity, also called food intolerance.
Trendy food intolerance tests aren't accurate, but they fuel our obsession with what we can and cannot eat.
According to a definitive report compiled for the National Institute of Allergy and Infectious Diseases by a 25-member panel of experts, a big part of the problem is misdiagnosis, from overreliance on two tests a skin-prick test and a blood test for antibodies that can produce misleading results.
The only test that can definitively establish a food allergy is a so-called oral challenge, in which the patient ingests the suspect food and waits for a reaction. This can be safely done only by an experienced health professional with emergency treatment at hand in case of a severe reaction.
IgG molecules mediate interactions of cells with different cellular and humoral mechanisms. IgG antibodies signify exposure to products—not allergy. IgG may actually be a marker for food tolerance, not intolerance, some research suggests...But given the lack of correlation between the presence of IgG and physical manifestations of illness, IgG testing is considered unproven as a diagnostic agent as the results lack clinical utility as a tool for dietary modification or food elimination.
Because false positives and false negatives are common, it's recommended that children only undergo allergy tests when absolutely needed. For children who are suspected of having a food allergy, an oral food challenge, which tests for an actual allergic reaction, is a much more useful test than a skin prick or blood test.
More and more consumers are being duped by diagnostic tests that are unproven, misleading and, in some cases, of no scientific basis whatsoever.
All manner of diagnostic tests can now be bought directly from online retailers or high street stores, without any input from a regulated health professional.
The consequence is that people often receive incorrect medical diagnoses and inappropriate or potentially harmful treatments that they do not need.
Unreliable test results can lead to unnecessary changes in your lifestyle.
Diagnosing allergies can be difficult. A doctor will often go through several steps before making a diagnosis, including specialized tests, a comprehensive interview about your ailments, and a physical exam. But it can sometimes take several months to get a correct diagnosis. Much like a detective working on a case, your provider will need to work by collecting information from you and from the different tests they organize. Together, you may need to test a few different strategies, such as avoiding possible triggers and then reintroducing them. This process can be slow, frustrating, and anxiety provoking. It’s no surprise, then, that many people are drawn to alternative allergy testing. Such tests can be a tempting way to get a quick answer about your allergies. But most alternative allergy tests do not have any science behind them. In other words: If a test sounds too good to be true, it probably is. And in general, these tests are more likely to do harm than good. With this in mind, here’s a guide to help you educate yourself about deceptive allergy tests.
Setting the standard in allergy diagnostics.
Radioallergosorbent testing (RAST) detects allergen specific IgE in the blood. They are used when skin prick tests (the preferred allergy test) is not suitable or not available. It is important to remember that allergy tests cannot be used on their own and must be interpreted in conjunction with symptoms and clinical history
The nice thing about allergy skin testing is you get information about what you’re allergic to during your visit to the allergist. You don’t have to wait two weeks for lab tests to come in.