Question:
I've been reading up on shrimp allergy and I am confused because I
cannot seem to find reference to my symptoms. When I eat shrimp I
experience acute itching inside the mouth and throat, nausea, and
vomiting. Veined cheeses and large quantities of raw mushrooms also
cause mouth-itching, but the reaction is much milder and not followed
by nausea or vomiting. The symptoms first appeared around puberty,
which is also when penicillin started giving me hives. No symptoms
are produced by cooked mushrooms or by other seafood or drugs.
I have so many questions. Is my reaction to shrimp really an allergy?
Why only shrimp and no other shellfish? Is it related to my
fungus/mold reaction? What kind of compound(s) could be at fault? Is
it possible I'm not allergic to shrimp at all, but to some fungus or
mold growing within the shrimp? If cooking mushrooms breaks down the
compound(s), why does cooking shrimp appear ineffective? Or might it
be effective if the shrimp were cooked longer and/or hotter than
convention calls for? (I have not experimented....)
Answer:
Some background information may help clear up some issues. The
symptoms you describe match food allergy symptoms. There are other
possibilites but given that your report consistent problems, I'd
stick with a food allergy. First, don't eat any more shellfish until
you are evaluated for shellfish allergy - it can become a life
threating reaction at any time after sensistization has happened.
Allergic reactions are not permanently consistent but they do tend to
get worse with continued exposure. It's your body's way of saying
"stop doing that". Heed the warning. Allergies operate by several mechanisms; this would likely be IgE
mediated. It is a reaction to specific proteins to which the body has
become sensitized. Cross reaction to similar proteins in related
species is common and well know. Shellfish is not a closely related
group, it actually spans several phyla of the animal kingdom. The
mold/fungus problem is probably an allergy to another protein. It is
not unusual for people to react to several unrelated proteins such as
dog and ragweed pollen. You do not have to react to all agents at the
same intensity. Cooking acts to change the 3 dimensional structure of
proteins thus usually changing binding affinty to receptors. Given
that cooking shrimp does not eliminate the reaction, the shrimp
protein causing the problem is not changed enough to stop the
response.
One thought that comes to mind is sulfite sensitivity, and I hear shrimp is
often treated with sulfite preservative. Maybe that's why other shellfish
don't trigger allergic reactions? But I must admit this is just an outside
possibility, not a diagnosis on my part. I've eaten blue-veined cheeses such as French Roquefort and Danish blue, but
never caught onto the sharp flavor that I could never find pleasant.
As to other shellfish you eat with no adverse reaction, you are not specific.
Are they arthropods (crab and lobster, for example), or molluscs (such as clams,
oysters, squid and octopus)?
maybe you can say, would somebody strongly allergic to
arthropod shellfish, such as shrimp, likely be also allergic to mollusc
shellfish? I don't want to advise anybody to eat something likely to be
life-threatening! All seafood really -- no reactions have been produced by any fish,
eel, squid, octopus, crab, lobster, crayfish, clam, scallop, conch,
snail, mussel, or oyster that I've eaten, many of which I've had both
cooked and raw.
