Better Health: Smart Health Commentary Better Health (TM): smart health commentary

Article Comments

Myth Buster: Seafood Allergies Do Not Increase Risk Of Allergies To CT Contrast Dyes

It is a prevalent belief out in the medical (and lay public) community that patients with iodine or seafood allergy can not receive contrast when undergoing certain radiological tests like CT or MRI scans. The concern is that contrast contains minute amounts of free iodide and as such, IV administration of this material puts the patient at risk of a life-threatening anaphylactic reaction.

Contrast is often given in these tests as it traces out bloodflow enabling the physician to see organ and mass architecture much more clearly allowing for improved accuracy in seeing anything abnormal.

Well… rest assured that patients with iodine and seafood allergy CAN receive contrast without any significant increased risk of an allergic reaction as compared to other allergies.

In a large study encompassing 112,003 patients, only 5% had a reaction. The relative risk of a reaction in patients with seafood allergy was 3.0 compared with 2.9 for those with allergy to eggs, milk, or chocolate; 2.6 for those with allergy to fruit and strawberries; and 2.2 for those with asthma [7]. In other words, a seafood allergy increases the risk of a contrast reaction by about the same factor as does any other allergy. At least 85% of patients with seafood allergy receiving IV contrast material will not have an adverse reaction.

Reference:
Formation of potential antigens from radiographic contrast media. Acta Radiol 1987; 28:473-77
Immunologic basis for adverse reactions to radiographic contrast media. Acta Radial 1990; 31:605-612
Contrast media reactions: experimental evidence against the allergy theory. Br J Radiol 1984;57: 469-173
Adverse reactions to intravascularly administered contrast media. AJR 1975;24: 145-152

*This blog post was originally published at Fauquier ENT Blog*


You may also like these posts

Read comments »


Comments are closed.

Return to article »

Latest Interviews

IDEA Labs: Medical Students Take The Lead In Healthcare Innovation

It’s no secret that doctors are disappointed with the way that the U.S. healthcare system is evolving. Most feel helpless about improving their work conditions or solving technical problems in patient care. Fortunately one young medical student was undeterred by the mountain of disappointment carried by his senior clinician mentors…

Read more »

How To Be A Successful Patient: Young Doctors Offer Some Advice

I am proud to be a part of the American Resident Project an initiative that promotes the writing of medical students residents and new physicians as they explore ideas for transforming American health care delivery. I recently had the opportunity to interview three of the writing fellows about how to…

Read more »

See all interviews »

Latest Cartoon

See all cartoons »

Latest Book Reviews

Book Review: Is Empathy Learned By Faking It Till It’s Real?

I m often asked to do book reviews on my blog and I rarely agree to them. This is because it takes me a long time to read a book and then if I don t enjoy it I figure the author would rather me remain silent than publish my…

Read more »

The Spirit Of The Place: Samuel Shem’s New Book May Depress You

When I was in medical school I read Samuel Shem s House Of God as a right of passage. At the time I found it to be a cynical yet eerily accurate portrayal of the underbelly of academic medicine. I gained comfort from its gallows humor and it made me…

Read more »

Eat To Save Your Life: Another Half-True Diet Book

I am hesitant to review diet books because they are so often a tangled mess of fact and fiction. Teasing out their truth from falsehood is about as exhausting as delousing a long-haired elementary school student. However after being approached by the authors’ PR agency with the promise of a…

Read more »

See all book reviews »