"Iodine-based contrast agents are widely used for CT and other X-ray studies. They light up blood vessels and enhance perfusing tissue. These agents are essential for diagnosing everything from clots, to tumor, to bleeding. Unfortunately, many patients do not get contrast studies they may benefit from, due to unnecessary confusion about allergies.

The most important step to avoiding confusion is to start calling contrast agents by their names, as you would do for any other drug, and to remove 'iodine' from your allergy vocabulary. Like antibiotics, there is more than one kind of contrast agent. Radiologists routinely dictate the name of the agent used in their study reports, so if a reaction occurs, the information is readily available. The problem comes when we do not distinguish one agent from another. Most patients with a prior reaction were never told the name of the drug they received, and they incorrectly assume that an allergy to one means allergy to all. Not so, just like with other classes of medications."

Cullen Ruff is a radiologist and author of Looking Within: Understanding Ourselves through Human Imaging. (https://amzn.to/3qEL23Z)

He shares his story and discusses his KevinMD article, "Think you have an iodine allergy? You may want to reconsider." (https://www.kevinmd.com/blog/2018/08/think-you-have-an-iodine-allergy-you-may-want-to-reconsider.html)