First of all there is a real link between shell fish and iodine allergy.
If you have a real iodine allergy, you may be allergic to iodine salt
to. I mean in some countries, for instance the Netherland, so can get
several types of kitchen salt, one is called Nezo the other Jozo. The
Jozo variety is ordinary sodium chloride, but some iodine has been
added for diet supplementation. In most places people have a shortage
of iodine in their diet, and this needs to be supplemented.
Therefore it might be that the salt used in a foreign country contains iodine.
The following website gives more details about the link between iodine
and shell fish allergies. This might be very useful to you also . See
link below
Good luck,
http://www.wdxcyber.com/ngen22.htm
Does Iodine Allergy Mean a Shellfish Allergy Too?
Frederick R. Jelovsek MD, MS
"I am highly allergic to iodine. During surgery recently one of the
medical attendants told me if I was allergic to iodine I must be
allergic to crab and lobster. I actually years ago had a reaction to
crab. Are there any other things I should be wary of?"
Donna
Allergies are a serious business. Sometimes a skin rash is the main
manifestation of an allergy but it can also range from
gastrointestinal upset to asthmatic wheezing and even to death (1).
People who are allergic to one compound may also have other allergens
they are sensitive to. For some reason certain allergies get linked
together even though they may be totally unrelated. This is what has
happened with iodine and shellfish. There is no actual relationship
between iodine allergy and the various seafood allergies. You could
have a reaction to both iodine and to ingested crab, but it is much
more likely that you are not truly allergic to either.
A true food allergy such as that to shrimp or crab starts within about
thirty minutes after ingestion. The reaction is to a muscle protein in
the food. Since a true allergic reaction can be life-threatening,
intravenous glucocorticoids, antihistamine and sometimes subcutaneous
epinephrine is required just like a bee sting kit for people allergic
to bees (2). To know for sure about both the iodine and the crab, you
should see an allergist and at least be skin tested or use one of the
home tests using IgE antibodies to see.
Most allergies to xray contrast media are to the specific media
itself, not necessarily the iodine component. It just so happened that
when most of the allergies to xray contrast dyes were initially
reported that all of the dyes contained iodine in some form so it was
assumed that the iodine was the allergen. There are also allergies to
non-iodine containing contrast media which are almost as common as to
the iodine containing ones. Therefore you have to have a skin test to
the specific contrast media to know for sure.
Does an allergy to iodine mean I cannot have iodized salt?
No, it does not. Iodine is a natural element and part of many proteins
in the body. Iodized salt is not known to cause an allergic reaction.
Even if you have a skin sensitivity to iodine containing products, you
can still ingest iodized salt without worry.
Iodine contact allergies are sometimes seen to providone-iodine
(Betadine®) scrub used as surgical preps. In one study, 10 people who
had skin reactions to providone-iodine were further tested and only
one was found to be skin allergic to the iodine, 5 were allergic to
the providone-iodine solution itself and the other 4 just had direct
skin irritation reactions but not allergic responses (3).
Iodinated contrast material used in certain x-ray studies has the same
variability as far as true allergic responses. One study of 165 people
who had reactions to iodine containing radiographic contrast material
identified only 2-3% who had true allergic responses as measured by
IgE antibody response (4).
Is a shellfish allergy the same as an iodine allergy
An allergy to shrimp or crab or salmon, for example, has nothing to do
with allergy to iodine. A person could be allergic to both but the
allergy to shrimp is due to a protein in the shrimp, not to iodine.
Identified seafood allergens belong to a group of muscle proteins,
such as the parvalbumins in codfish and salmon and tropomyosin in
crustaceans (shrimp, lobster and crabs). In addition, tropomyosin is a
cross-reactive allergen among crustaceans and mollusks such as oysters
and scallops (5). Eating the seafood is not the only way to have an
shellfish allergic reaction; it has also been reported to be air-borne
in places such as a fish market (6).
If I am allergic to shrimp, am I likely to be allergic to other seafood?
Yes. There are some seafood allergies that tend to run together(7).
People allergic to shrimp may also be allergic to crab, lobster, clams
and oysters. Salmon, trout and mackerel allergy may frequently occur
together just as does cod and tuna, and octopus and squid.
The most accurate way to find out what one is allergic to is through
skin testing by an allergist. If someone seems to have multiple
seafood allergies, however, the true test is to be given the actual
food in a double-blind, placebo-controlled food challenge,
administered under the care of an allergist or other physician (8).
Blood tests for food antibody specific IgE are not quite as accurate
as skin tests or food challenges, however you do not have to be
exposed to the allergen (and its probably allergic response) in order
to be diagnosed.
Why can I sometimes eat shellfish and other times I get quite sick?
Not all reactions to seafood are allergies to the seafood protein
itself. In fact a parasite called anisakiasis which frequently
contaminates seafood is a major cause of gastrointestinal upset that
many people interpret as a food allergy. This parasite is killed by
deep freezing the shellfish so if you find you can tolerate shrimp
that has been frozen but sometimes get sick eating fresh shrimp, it
may be the parasite contamination rather than a seafood allergy (9,
10).
Also, you may just be having a show of food intolerance and not an
allergic response. Food intolerance and food allergies are NOT the
same. A food allergy that stimulates the immune system to cause a
serious reaction such as:
hives, itching or skin eczema
swelling of the lips, face, tongue and throat, or other parts of the body
wheezing, nasal congestion or trouble breathing
dizziness, lightheadedness or fainting
is much more serious than a food that your body may be sensitive to
resulting in nausea, vomiting, cramping and diarrhea but not a true
allergic response.
What is food intolerance?
Food intolerance is a direct irritation of the body by a food or
associated chemical or toxin rather than one which stimulates the
body's own immune system to attack itself. Food intolerance may be due
to the lack of an enzyme such as lactose which results in many people
having a problem eating milk, ice milk or other milk products without
becoming bloated along with cramping, diarrhea and excess gas.
Sometimes food may contain a toxin from bacteria that causes you to
react adversely. This does not mean that you cannot ever eat that food
again; it just means you should not eat that food when it is
contaminated again. Mushrooms, rhubarb, and spoiled tuna or other fish
are foods more likely to be come contaminated with toxins. It can be
very difficult to differentiate an intolerance to the food itself or
to a substance or ingredient used in the preparation of the food. This
is especially true of foods containing lactose, wheat or sulfites. For
example, wheat can cause a food intolerance but it also can cause an
immune allergic response known a celiac disease or sprue.
On the other hand, if you are truly allergic to a food such as:
cow's milk
eggs
peanuts
Wheat
soybeans
fish
shellfish
tree nuts
even a small amount could give you a serious health reaction. If you
suspect that any food is causing you a serious allergic response, be
sure to see an allergist to have it diagnosed thoroughly. Skin tests
for allergies are considered the best way to diagnose an immune
response but sometimes you may have much less of a reaction by just
having a blood test known as an in-vitro allergen-specific IgG or IgE
antibody test. The home tests use a drop or two of blood from a finger
stick which check IgE allergic sensitivities.
Does an iodine allergy mean I cannot have xray dyes?
Again no, it does not. But you need to let the radiologist know about
the iodine allergy. Sometimes the dye used can be switched to a non
iodine containing contrast material and at other times it may just be
suggested to have a skin sensitivity allergy test to the actual dye to
be used if there is not a suitable substitute dye available. |
