I had contrast iodine injected for a Ct scan when I was 18.
It caused me to develop a horrendous allergy to iodine including all fish. Shellfish causes anaphylaxis but even freshwater fish causes milder reaction. I need to be extra careful when I go to a doctor because they always seem to want to slather some iodine product on me. So I need to remind everyone I come in contact with about it.
My endo told me it is much more common in type 1 people to develop these kinds of allergies and iodine is one of the big triggers. I don’t know what I will do if I ever need a radioactive iodine treatment for hyperthyroidism