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Mr. McMinn If someone is allergic to
certain metal jewellery, what are the chances of
having a deep tissue allergy? What is the most
accurate way of testing someone for a deep
tissue allergy?
It is estimated that approximately 10% of the
population shows skin (cutaneous) allergy to
metal products like costume jewellery. In terms
of deep tissue allergy the leading authorities
agree that, ‘clinically important metal
hypersensitivity in patients with metal-on-metal
bearings appears to be low’. In our series only
0.3% of patients required a revision for
presumed metal debris reaction. It is not clear
if these cases represent a true allergic
response or an expected response to excess
debris. There is no proven way of testing for
deep tissue allergy. Cutaneous testing works
through a different mechanism to deep tissue
allergy, and therefore is not of much benefit.
Lymphocyte transformation testing is described
as one of the ways of testing potential deep
tissue allergy but is not proven. |
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Dr. De Smet writes that although very rare, a reaction can
occur after a BHR hip replacement. The following is a story
about a problem that Dr. De Smet thinks is associated with a
metal sensitivity in a BHR.
November 08, 2007
Metal allergy - an OS writes
While metal allergies are indeed rare, they can be (or have the
effect of being) all too real.....
My wife is 31 yrs old and had her right hip resurfaced 2 years
ago by Dr. De Smet (she originally broke her hip around 10
years, developed AVN, had an osteotomy 7 years ago, developed
arthritis, which ultimately led us to Ghent - can't say enough
about the experience there).
Around a month ago she started experiencing terrible hip pain.
X-rays (and a CT Scan) show that the bone just below the bottom
end of the femoral cap is essentially dissolving (osteolysis).
Blood tests were performed and, while it is not an exact
science, there does appear to be sensitivity to both chromium
and nickel - chromium being one of the main by-products of the
resurfacing components.
While there certainly could be other factors at play (e.g.
improper load bearing due to prior surgeries/injuries or decay
of the cement used in the femoral cap [which, according to one
prominent surgeon I spoke to, can happen, particularly in cases
where the femoral head has already been significantly damaged]),
I don't believe it. Both of those factors can, I believe, be
worked through with exceptional surgical technique - and I have
the utmost confidence in De Smet.
According to De Smet, around 1 out of every 500 patients has
this type of reaction to the metal. To quote De Smet, "That
indeed is a possibility. Metal sensitivity is a risk of 1/500 in
my series. A lot of people do not believe it and say it is non
existing or very rare. If [metal] is the problem......she has
really bad luck".
We are now looking at a THR (which will most likely happen in
the next week or so) and, while there is no way to know for
certain whether a "metal allergy" is causing the problem, at
this point, we certainly can't risk having a MoM THR - ceramic
is the only option. Joel Feldman (Meg: De Smet - Sept 05)
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