Allergy tests of no proven value
There are an enormous range of allergy and intolerance tests available. Some have been proven to be reliable and accurate, while others seem to be of no value.
by Dr Adrian Morris
Many unconventional allergy tests are available which purport to diagnose a number of maladies. Tests range from electro dermal tests to trace metal estimation in hair samples . These un-validated tests are sometimes promoted by complementary and alternative medicine (CAM) practitioners. Superficially many of these tests sound plausible, but are based on unproven theories and explained with simplistic physiology. Most of these tests diagnose non-existent illnesses [2, 3], are a waste of money, and divert attention from actual allergies thus delaying conventional treatments that offer genuine allergy relief.
CAM practitioners base their allergy tests on controversial theories about what might cause allergies. Examples include:
- Chemical fumes from cleaning solvents, petrol, paints and perfumes
- Electromagnetic radiation from power lines and electronic devices
- Food with traces of colourings, antibiotics, pesticides and preservatives
- Micro-organisms such as Candida albicans and exotic parasites
- Prescription and over-the-counter medication
- Multiple foods such as wheat, yeast, sugar and coffee
- Endogenous hormones particularly progesterone.
- Leaky gut syndrome and dysbiosis.
Who “tests” or validates the tests?
Some practitioners cite anecdotal case reports and clinical studies in fringe medical journals. Individuals may well develop non-specific irritant reactions and side-effects to medication or vaso-active amines occurring in foods but this is of a non-allergic nature. Environmental or multiple chemical sensitivities, systemic candidiasis, attention deficit disorder (ADDH) and chronic fatigue are commonly diagnosed as resulting from “allergies” to various environmental chemicals and naturally occurring fungi and parasites. Although Candida can cause vaginitis and oral thrush, there is no convincing evidence that systemic infections are related to allergy [4, 5]. Exotic parasite infestations are diagnosed on a droplet of blood with no convincing supportive evidence. Few of these tests are ever validated, checked or run with control samples. None are routinely re-calibrated or appraised with recognised scientific checks of equipment.
A report in Daily Mail newspaper reported on an adolescent girl who tested “positive” to 33 toxic chemicals found in household cleaners, foods and the modern “environment”. This caused enormous consternation to her caregivers but when one considers the accuracy of these tests and whether traces of chemicals in hair samples or other body fluids have any health implications at all, the unnecessary anxiety generated by these “tests” becomes apparent.
Once many of these factitious conditions are diagnosed, the naïve patient is then put onto various elimination diets, rotation diets and loads of unnecessary vitamin and trace element supplements. Herbal remedies such as ephedria (now banned in USA), spirulina, grape seed oil, nettle, vitamin C and more recently flax seed oil are prescribed and symptom improvement may be related to undisclosed “salting” with steroids in these so-called natural remedies . The illegal addition of corticosteroids to these “natural and traditional” remedies gives them obvious therapeutic effect but may result in dangerous side effects if used for prolonged periods of time (7).
It is the author’s and Warner’s experience that health journalists are unlikely to investigate or expose these pseudo-scientific tests as fallacious for fear of alienating their “complementary medicine” readership (8). Some of these CAM allergy tests may someday be proved to be safe and efficacious, but to date; no convincing studies have ever proved any of their efficacies in diagnosing allergies.
This article will review the common “allergy tests” used by complementary and alternative medical practitioners.
The Leucocytotoxic Test (Bryan’s Test)
Bryan’s Leukocytotoxic test was originally developed in 1956 by Black, and further elucidated by Bryan in 1960. The basis of the test is that if the patient’s white blood cells are mixed with the offending allergen, they swell. The test then measures any swelling of the leukocytes and if a certain threshold of swelling is measured, using a Coulter Counter – a Positive result is recorded. Studies to date have shown poor correlation between this test and clinical allergy. The marketers, who rely on anecdotal evidence of efficacy, do not mention these disappointing clinical studies. A large number of allergens are tested for and patients are usually positive to a number of foods, additives and other agents. Personal communication with Katelaris in Australia and Steinman in South Africa plus Lieberman’s study in USA (9) confirm that preliminary studies on the ALCAT test found no diagnostic accuracy. At present the test is also marketed under the name “Nutron”. Despite claims to the contrary, no large studies have ever shown the test to be accurate despite it being available for over 50 years!
The original protagonists of the ALCAT test (which includes the Leucocytotoxic test and Nutron Test) could only site a few non-peer reviewed congress abstracts as evidence that it worked. While the antagonists (personal communication with the leading opinion leaders in the field of food allergy such as Bindslev-Jensen, Potter and Katelaris) have substantial data on record to show a poor diagnostic accuracy. The lack of mainstream acceptance of these tests is often blamed on “a conspiracy” by the larger multinational diagnostic companies to try and remove the defenceless opposition from the market. This perception is not a true reflection of the situation.
The IgG ELISA Allergy Test
Another allergy test of questionable accuracy is IgG ELISA test. This test measures IgG and IgG4 antibodies to various foods which should not be confused with IgE antibody testing in conventional RAST and ImmunoCAP. Most people develop IgG antibodies to foods they eat and this is a normal non-specific response indicating exposure but not sensitisation. There is no convincing evidence to suggest that this test has any allergy diagnostic value [10, 11]. In fact, the IgG response may even be protective and prevent the development of IgE food allergy! IgG4 antibodies produced after high level cat allergen exposure in childhood confer cat allergy protection and not sensitisation .
Applied Kinesiology (Muscle Testing)
Applied Kinesiology was developed in the USA by Goodhart in 1964 and relies on energy fields within the body to diagnose allergy and intolerance. Kinesiology is popular with Chiropractic practitioners in the United Kingdom. In this test, the practitioner tests the patients muscle strength when the allergen is placed in a vial in front of them. The shoulder strength (Deltoid muscle) is usually tested for weakness. The patient holds out their arm and the practitioner applies a counter pressure – if the patient is unable to resist the counter pressure, the test is considered positive to that allergen. The antidote to the allergy is then also held in front of the patient and if their weakness is reversed – this indicates it is the correct antidote. There are a number of variations to the technique of muscle testing and many practitioners complement the test by holding a magnet in front of the patient. There is no convincing evidence that this test has any useful role to play in allergy diagnosis [1,13].
VEGA Testing (Electrodermal Testing)
This test was developed by German physician Dr Reinhold Voll in 1958. The VEGA Test (or Electrodermal Test) involves measuring electromagnetic conductivity in the body using a Wheatstone bridge Galvanometer. The patient has one electrode placed over an acupuncture point and the other electrode is held while a battery of allergens and chemicals are placed in a metallic honeycomb. A fall in the electromagnetic conductivity or a “disordered reading” measured indicates an allergy or intolerance to that allergen. Newer transistorised/computerised versions of the original VEGA or Voll test are called Dermatron, BEST, Quantum and LISTEN Systems which have a similar application and give more rapid results. Some proclaim to test for 3500 allergens in 3 minutes! Katelaris et al [14) and Holgate  performed independent double blind testing, comparing VEGA testing with conventional testing in known allergy sufferers, and the VEGA Tests had no reproducibility or diagnostic accuracy at all . The manufacturer’s aggressively promote the test and offer free training courses for potential “allergy” diagnosticians.
Hair Analysis Testing in Allergy
Hair is analysed for allergies in two ways. First of all, the hair is tested for toxic levels of heavy metals such as Lead, Mercury and Cadmium and then deficiencies of Selenium, Zinc, Chromium, Manganese and Magnesium. There is no scientific evidence to support the hypothesis that these heavy metals have any bearing on allergic diseases. Hair samples are usually sent away for analysis and numerous studies have failed to find any accuracy in hair analysis diagnosing allergies . Another hair test is called Dowsing. The dowser swings a pendulum over the hair and an allergy is diagnosed if an altered swing is noted.
Suspected allergens are placed in filter papers over the skin of the forearm. A bright light is shone through the ear lobe or back of hand. At the same time the pulse is assessed. If the filter paper contains an allergen to which the patient is allergic, the pulse increases by 12 or more beats per minute. To date, no scientific data is available to validate this test .
The allergen is applied sublingually, or by skin injection. Increasing test doses are given until a wheal appears on the skin (Provocation Dose), the dose is then decreased until the wheal disappears. This is the Neutralisation dose which is used to treat the allergy and “desensitise” the patient. This test has also not been validated by studies and has no diagnostic reliability in allergy or treatment .
Nampudripad’s Allergy Elimination Technique (NAET)
NAET has to be the most unsubstantiated allergy treatment proposed to date. It consists of a combination of methods of diagnosing and treating allergy such as kinesiology, Vega testing and acupuncture. It was proposed in 1983 by American chiropractor Devi Nampudripad, hence Nampudripad’s Allergy Elimination Technique or (NAET). The premise is that allergy (contrary to our current understanding), is due to some form of internal energy blockage triggered by abnormal energy fields in the brain. Nampudripad proposed that after 20 or so treatments she can re-programme the brain and body energy flow and eradicate all allergies and many other diseases affecting mankind. However, as a cause of allergies, energy flow and electrical fields in the body have not ever been proven.
Live Blood Analysis
With the aid of a simple microscope and a short course in microscopy, many CAM practitioners are now professing to be able to diagnose all sorts of chronic ailments including allergies. The finger is pricked and a fresh blood specimen is examined under the light microscope for blood cell ‘deterioration’, rare parasites, or coagulation disorders. It is impossible to determine parasitaemia, bacteraemia or coagulation abnormalities on a drop of blood, without specialised stains and testing methods.
Stool analysis and microscopy for yeasts and parasites
Fringe laboratories especially in the USA operate a postal service, analysing stool samples for bizarre metabolites and an array of exotic parasites and organisms that are purported to cause non-specific symptoms supposedly related to lifestyle allergies. Laboratories in the USA will do a full assessment of exotic micro-organisms, bizarre bio chemicals and proteins on a stool sample and send a “comprehensive” and visually impressive report of these.
Beware of anecdotal and unsubstantiated allergy tests
There are a plethora of so-called tests for “Intolerances” including urine, stool and saliva as well as Bio-resonance (Vibrational Medicine) and Iridology. These tests are often promoted as “wonder” diagnoses and anecdotal stories of lifelong allergies finally being accurately diagnosed abound. It would be naïve for any medical practitioners to accept these individual anecdotal reports of diagnostic efficacy without any scientifically validated studies to prove their worth. We often read about similar tests in the media and unsuspecting patients flock to part with their hard-earned money. Conventional medical practitioners may be accused of bias against these supposedly simple and “cheap” tests and feel pressurised to try them out. On the other hand, a convincing CAM practitioner armed with an impressive allergy-diagnosing “contraption” can talk even the most sensible patient into believing their pseudo-scientific explanations and anecdotal reports of allergy cures. Once the patient realises that they have been incorrectly diagnosed, they may feel embarrassed, put the matter down to bad experience and hardly ever complain about the treatment or costs involved. For more information on these dubious tests visit the Quackwatch website at http://www.quackwatch.com/
Unproven techniques in allergy diagnosis
“Mainstream allergy diagnosis and treatment is based on classical allergy testing which involves well-validated diagnostic methods and proven methods of treatment. By contrast, a number of unproven tests have been proposed for evaluating allergic patients including cytotoxic food testing, ALCAT test, bioresonance, electrodermal testing (electroacupuncture), reflexology, applied kinesiology a.o. There is little or no scientific rationale for these methods. Results are not reproducible when subject to rigorous testing and do not correlate with clinical evidence of allergy. Although some papers suggest a possible pathogenetic role of IgG, IgG4 antibody, no correlation was found between the outcome of DBPCFC and the levels of either food-specific IgG or IgG4, nor was any difference seen between patients and controls. The levels of these and other food-specific immunoglobulins of non-IgE isotype reflect the intake of food in the individual and may thus be a normal and harmless finding. The so-called ‘Food Allergy Profile’ with simultaneous IgE and IgG determination against more than 100 foodstuffs is neither economical nor useful for diagnosis. DBPCFC must be the reference standard for food hypersensitivity and any new test must be validated by it. As a result, all these unproven techniques may lead to misleading advice or treatments, and their use is not advised.”
Unproven techniques in allergy diagnosis.
J Investig Allergol Clin Immunol 2005;15(2):2-90
Testing for IgG4 against foods is not recommended as a diagnostic tool
“Serological tests for immunoglobulin G4 (IgG4) against foods are persistently promoted for the diagnosis of food-induced hypersensitivity. Since many patients believe that their symptoms are related to food ingestion without diagnostic confirmation of a causal relationship, tests for food-specific IgG4 represent a growing market. Testing for blood IgG4 against different foods is performed with large-scale screening for hundreds of food items by enzyme-linked immunosorbent assay-type and radioallergosorbent-type assays in young children, adolescents and adults. However, many serum samples show positive IgG4 results without corresponding clinical symptoms. These findings, combined with the lack of convincing evidence for histamine-releasing properties of IgG4 in humans, and lack of any controlled studies on the diagnostic value of IgG4 testing in food allergy, do not provide any basis for the hypothesis that food-specific IgG4 should be attributed with an effector role in food hypersensitivity. In contrast to the disputed beliefs, IgG4 against foods indicates that the organism has been repeatedly exposed to food components, recognized as foreign proteins by the immune system. Its presence should not be considered as a factor which induces hypersensitivity, but rather as an indicator for immunological tolerance, linked to the activity of regulatory T cells. In conclusion, food-specific IgG4 does not indicate (imminent) food allergy or intolerance, but rather a physiological response of the immune system after exposition to food components. Therefore, testing of IgG4 to foods is considered as irrelevant for the laboratory work-up of food allergy or intolerance and should not be performed in case of food-related complaints.”
Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report*
Stapel SO, Asero R, Ballmer-Weber BK, Knol EF, Strobel S, Vieths S, Kleine-Tebbe J
Allergy 2008 July;63(7):793-796
- Allergy: Conventional and alternative concepts. The Royal College of Physicians, London, in Clin Exp Allergy: 22 :suppl 3 ;Oct. 1992
- American Academy of Allergy: Position statements – controversial techniques. J Allergy Clin Immunol 1981;67:333-338
- Sethi TJ, Lessof MH, Kemeny DM, Lambourn E, Tobin S, Bradley A. How reliable are commercial allergy tests? Lancet 1987;i: 92-94
- Crook WG. The yeast connection. Jackson, Tennessee: Professional Books, 1984
- Candidiasis hypersensitivity syndrome. Executive committee of the American Academy of Allergy and Immunology. J. Allergy Clin Immunol 1986; 78:271-273
- Niggemann B, Gruber C. Side effects of complementary and alternative medicines. Allergy 2003 58(8) 707-16
- Ramsay H M, Goddard W, Gill S, Moss C. Herbal creams used for Atopic Eczema in Birmingham UK, illegally contain potent corticosteroids. Arch Dis Child 2003 85(12) 1056-7
- Warner J. Allergy and the media. Pediatr Allergy Immunol 2005; 16: 189-90
- Lieberman P, Crawford L, Bjelland J et al. Controlled study of cytotoxic food test. JAMA 1975; 231:728-30
- Lay Advisory Committee. Allergy and allergy tests: A guide for patients and relatives. The Royal College of Pathologists (London) June 2002:1-10
- Atkinson W, Sheldon TA, Shaath N, Whorswell PJ. Food elimination based on IgG antibodies in Irritable Bowel Syndrome: a randomised controlled trial. GUT 2004;53:1459-1464
- Kihlstrom A, Hedlin G, Pershagen G, Toye-Blomberg M, Harfast B, Lilya G. Immunoglobulin G4-antibodies to rBet v 1 and risk of sensitisation and atopic disease in the child. Clin Exp Allergy 2005; 35: 1542-49
- Garrow JS. Kinesiology and food allergy. Br Med J 1988; 296:1573-1574
- Katelaris CH, Weiner Jm, Heddle RJ, Stuckey MS, Yan KW. Vega testing in the diagnosis of allergic conditions. Med J Australia 1991; 155:113-114
- Lewith GS, Kenyon JN, Broomfield J, Prescott P, Goddard J, Holgate ST. Is electro dermal testing as effective as Skin Prick Testing for diagnosing allergies? A double blind randomised block design study. BMJ 2001; 322:131-134