Allergy Tests: The Good, the Bad and the Ugly

There is seldom a perfectly reliable test in medicine, and all of the tests listed above have varying degrees of sensitivity and specificity. They are good but they are not perfect, and they are not an end in themselves. They must always be interpreted in the context of the whole of things. This is true of all medical tests, but never more so than in the case of allergy. The dietary and chemical tests, in particular, are subjective. They depend on a patient's experience of symptom relief and recurrence. They are, therefore, at the mercy of the placebo effect, and all of the other variables of human nature. In spite of this obvious drawback, many patients find lasting relief from their symptoms by using these methods.

We cannot leave this topic without reference to the plethora of 'alternative allergy tests' on offer: vega testing, radionics, pendulum swinging, divination, kinesiology, pulse testing, etc. These all claim the ability to tell you, in a jiffy, what you're allergic to. A few blood tests also lay claim to the same magical ability. The latter are more ominous than the former because they have a semblance of science about them, but it's nothing more than pseudo-science. There is no rational basis for any of these tests; they are neither sensitive nor specific, and they give rise to endless false positives and negatives. In short, they are useless. Their attraction, from the patient's point of view, is that they offer a quick and easy solution, and they preclude the need for painstaking dietary investigation.

Many food-intolerant patients have been told by orthodox medicine that they are 'not allergic' when they know well they are. Thus dismissed, they seek out a practitioner who will respect their intelligence! Perhaps you are one of these? 'I had my allergies tested in this way,' you may say, 'and it worked!' Great - I have no problem with that. You stopped eating certain foods and you got better. You probably do have food intolerance, but that does not justify the diagnostic method!

Let me illustrate what I mean. Imagine we have in front of us 100 people with food intolerance, and let's suppose they are all eating a standard Western European diet. We put a dartboard on the wall, and we replace numbers on the board with the names of our staple foods. We don a blindfold and throw ten darts at the board. Then we tell all of our patients to avoid the following foods: wheat, yeast, sugars, dairy produce, caffeine, chocolate, and citrus fruit. We also throw in a few extras here and there on an individual basis to make it look good. Our result is guaranteed: 25 per cent will improve within fourteen days. We have just invented a new diagnostic test for allergies: it's the 'blindfold dartboard test'! We would vary it a little, of course. If we were dealing with a North American population, for example, we would advise our patients to avoid peanuts and com; and an Asian population would avoid rice and soy bean. Why? Because, as a general rule, we become intolerant to the foods we most commonly eat. Excluding these foods will therefore lead to an improvement in food-related symptoms.

However, there are several problems with our blindfold dartboard test:
1. it's not specific enough. Our patients do not know whether one, or two, or indeed all of the omitted foods are causing their trouble. The 'diagnosis' is incomplete.
2. it's not sensitive enough. It neglects the 75 per cent who do not improve, and leads them to believe they are not food-intolerant when they are.
3. It leads to incomplete treatment. Some patients have been advised to stick to very severe regimes for years on end. They are socially inconvenienced (to say the least), and they are at risk of nutritional deficiency.

In conclusion, then, our new test is quite useless - in spite of the fact that it 'works' some of the time.
Please understand that I have no wish to belittle alternative or complementary medicine in all of this. On the contrary, I believe it has a lot to offer, not least in its espousal of a holistic approach to medicine. Furthermore, the genuine practitioners of alternative therapies would share the concerns I have outlined above. Besides, the pseudo-scientific useless blood tests alluded to above are promoted by practitioners of orthodox training!

Source: My House Is Killing Me! The Home Guide for Families with Allergies and Asthma by Jeffrey C