Iodine Allergy?

Sometimes we hear about patients who have allergy to iodine. However, this goes against some of the things that we learned in medical school. Our thyroid glands make hormones that contain iodine, which are important parts of regulating how our bodies work. So if it is such an important hormone, how can anyone be allergic to it? Actually, they CANNOT be allergic to iodine. Typically, when people say that they are allergic to iodine, what they mean is that they have an intolerance of iodinated contrast dye that is used in some radiology procedures to take images of internal anatomy. Sometimes these are allergic reactions, and sometimes they are not. So now you know; you can’t be allergic to iodine!