If someone is born allergic to iodine, would they have a T3 and T4 problem as well?

Question

I'm confused about this part of the thyroid hormone...

Any help or explainations either way would belp a lot!

Thanks!

Answer 1

Marie is right about allergies to iodinated compounds. Moreover, people aren't born with allergies. The fetal immune system isn't mature enough.

Answer 2

Generally speaking, when someone says they have an "allergy to iodine," they have had a reaction to either contrast media used in radiology or to shellfish.  In both cases, it is almost certainly not actually the iodine that causes the reaction, but that used to be what people thought, so it's still a common idea.  They are most probably having a reaction to something else in the contrast (because even the non-iodized ones can cause reactions) or to a protein in the seafood.  This is borne out by the fact that people who know they have reactions to seafood are NOT more likely to have reactions to contrast media.  (People who have any autoimmune issue, including allergies, eczema or asthma, are more likely to have reactions in general, but it isn't always because of the same thing, if that makes sense.)

I have never heard of someone's having an allergy to dietary or elemental iodine (though there is even such a thing as an allergy to water--no joke--so there may be a case study out there), so T3 and T4 should not be an issue.  If there is such a case, it would be a huge problem, because you can't live without elemental iodine and thyroid hormone.

You do sometimes see a skin reaction to Betadyne or other such antiseptics that contain iodine, but that's a contact irritation and it also isn't correlated with reactions to contrast media.