Is electrodermal testing as effective as skin prick tests for diagnosing allergies? A double blind, randomised block design study

With regard to your article about Vega equipment, you conclude with
the line:

"It is difficult to connect this known pathophysiological mechanism
with any theory that embraces a change in whole body electrical
conductivity."

Perhaps your investigation failed because you examined it as a whole
body electrical phenomenom. It would be better if you looked at it from an
acupuncture viewpoint.

The Vega system of diagnosis only operates if the probe is placed on
an acupuncture point, i.e. an area of skin with a reduced electrical
resistance. Other skin surrounding the acupuncture point does not behave
in the same way.

Applied Kinesiology also uses acupuncture points in treatment, and
these points behave in a different way from non-acupuncture points, when
measured relative to the strength of a muscle.

The identification of these discrete points is vital to understanding
the nature of Vega testing.

Competing interests:  
I use a Veegatest apparatus in my daily practice.
I am a qualified and registered Naturopath.

I thank Dr Smith very much for his comments which I found fascinating.
What we were doing here was following up an observation which I made with
Krop
(done
at Krop's surgery) that suggested that Vegatesting could distinguish
between
proven allergic and non-allergic patients (1). We found that when we
repeated this in a much more rigorous manner with many more patients
(and
an
entirely double-blinded experiment), we were unable to reduplicate
the
results which we had originally observed. I entirely agree that the
situation is immensely complicated, that is why we chose such a
specific
test.

I note also John Heptonstall's comments on the Vegatest and again
cannot
disagree with them, but it simply wasn't what we were testing in the
context
of this particular experiment. The Vegatest may be measuring
something
in
relation to food intolerance and/or in relation to the selection of
appropriate homoeopathic remedies. We make it plain in the article
that
this has not been measured.

George Lewith

1. Krop J, Lewith G, Gziut W, Radulescu C. A double blind,
randomised,
controlled investigation of electrodermal testing in the diagnosis of
allergies.Journal of Alternative and Complementary Medicine. 1997; 3(3):
241-248.

Editor

Some years ago I supervised groups of my students carrying out a
couple of short studies into electrodermal testing with the Vegatest
apparatus.

I note that Krop, Lewith, Gziut and Radulescu (JACM Vol 3 No. 3,
1997. pp241-248, A Double Blind, Randomised, Controlled Investigation of
Electrodermal Testing in the Diagnosis of Allergies) concluded that
electrodermal testing "is a promising technique and should be the subject
of further scientific study".

I did not consider a 'food allergy' focus as electrodermal testing
has no direct, as Lewith et al have shown, relevance to 'allergy';
perceived wisdom was that Vegatesting is more to do with the, as yet
unclear, field of sensitivity or intolerance. However, it is very clear to
regular users of this apparatus that it is a valuable tool for identifying
sensitivities. I set my students the task of acertaining

1. Reproducibility of results (a common criticism of food allergy and
sensitivity testing systems)

2. Whether certain disorders could be linked, by Vegatest, to certain
food or environmental sensitivities. Regular use suggested this to be the
case; eg. anecdotally, asthma sufferers appeared to display a
preponderance of sensitivities within the cereal and fish groups, phenols,
and dust mite.

1. The first study concluded that certain sensitivities were more
reproducible than others, for example those involving chemical or
environmental substances as opposed to foods. To a Western Medical (WM)
scientist this appears to negate findings, why should the body's reaction
to food change within hours or days? Traditional Chinese Medicine (TCM)
scientists are more likely to ask 'why should the body's reactions to
foods not change by the hour or day? If our tastes change from meal to
meal, then why not the body's reaction to food'?

The hypothesis is that there may be different levels of
'sensitivity'; the strong reproducible ones such as environmental toxins,
the moderate ones which return when we see a patient going through a
relapse, the milder ones that are transient - rather like one's taste -
and the consistent ones that seem to relate to specific illnesses. We then
looked at the latter.

2. The team studied four illnesses, RA, asthma, rhinitis and migraine
retrospectively; they analysed results from Vegatests which had been
carried out by a single operator within the last 10 years.

They searched for the number of 'hits' for each food and
environmental sensitivity per disorder, and the percentage of patients
showing these hits; here are a few of the findings:-

For Rheumatoid Arthritis, 33.33% of cohort had hits for Beans,
Parsley, Pear, Pollens and Turkey, 25% had apple, carp, herring, juniper,
lobster, margarine, sour milk, peas, pineapple, rosemary, black tea,
orange, MSG and mercury. This illness produced the least conclusive spread
of hits.

For Migraine 39% showed high hit rate for EMF (electromagnetic field
stress - VDU, computer, fluorescent lighting etc. ), 35% for mite, 26% for
beer.

For Asthma the house dust mite scored highest hit rate for 53% of the
cohort, then trout, herring and dog for 35%.

For Rhinitis the highest hit rate was for EMF and Dog both with 53%
of cohort, then mite and halibut for 42 %, then candida for 37%, then
strawberries for 32%.

Although small inconclusive studies they did enlighten us and
provided more support for what had become common expectations from the
equipment witness the large proportion of patients who state they have
benefitted from Vegatesting.

I won't go into the TCM analysis of results here but my students did
produce an interesting TCM perspective on why certain sensitivities may
have appeared regularly for certain disorders; these deliberations make
sense to TCM but not yet to Western Medicine which has little
understanding of food and environmental considerations in illness - TCM
has for generations recognised diet, foods and environment as both
potentially health giving and potential pathogenic. EMF radiation was
easily recognised as a 'WIND' pathogen in TCM, fluctuating magnetic field
creates a microclimate of what TCM refers to as 'wind pathogen' and this
affects the liver predominantly hence eg. migraine could be expected to
derive from an environment having a strong fluctuating magnetic field.

We see 'sensitivities' that run in families, eg. potatoes and
tomatoes, possibly most of the more reproducible substances are common in
a family line; there must be some genetic continuation.

The recent information on blood type and diet (Dr. Peter D'Adamo, The
Eat Right Diet) is interesting; a 'cursory glance' suggested some measure
of correlation between Vegatest results and 'blood type considerations', a
focus for more research? The Vegatest employs acupoint impedance
measurements, TCM reminds us of the direct corelation between Blood and
Qi, is the Vegatest measuring some aspect of blood which correlates
directly with the electrical component of QI measured?

The old saying 'one man's meat is another man's poison' was also
reflected in these studies. People are seen to have their own particular
sensitivities, as well as those coincident with disorder type, and these
fluctuate according to current levels of stress, state of health etc.

Those involved in allergy, intolerance and sensitivity studies must
therefore adopt an open and objective disposition, not expecting each
person to carry the same or similar burden of sensitivities but
individual, and to some extent common reproducible ones; and that some of
these may fluctuate with taste while a smaller number will remain
reasonably reproducible.

Regards

John H.