Allergic Reactions to X-Ray Contrast Can Be Treated without Long Term Problems
Occasionally people having CT scans or other imaging exams will have an allergic-type reaction to the iodine contrast, but research has found that they can be treated safely without long term effects. In fact, almost all reactions are mild and more han 99 percent patients with them will get better within a day.
Radiologists at the University of Michigan hospitals in Ann Arbor studied nearly 85,000 intravenous injections of nonionic iodinated contrast media looking for allergic-type reactions. They analyzed both how the reactions were treated and whether there were any long term problems after a reaction.
They found that reactions were rare — 545 or about half a percent of all patients had some allergic-type reaction with 221 requiring treatment. Most were mild (418), some moderate (116), and 11 were severe.
Almost all — 99 percent — had symptoms go away within 24 hours. Only two patients, who had severe reactions, had problems lasting more than a day.
The most common treatment was Benedryl® (diphenhydramine) given to 145 patients. A few received corticosteroids, albuterol or ephinephine.
Although outcomes were generally very positive, the research team was concerned that errors were made in treating patients who had reactions. Richard Cohan, MD, who led the study, commented,
Commonly used medications can be administered safely; however, treatment errors are not uncommon and in a few instances can lead to patient morbidity. In our study, we found a number of instances in which non-recommended treatment was provided. These cases included the administration of oxygen by nasal cannula (rather than mask) and at lower than recommended doses, over-utilization of diphenhydramine (including to a few patients who were hypotensive), and the administration of higher than recommended doses of epinephrine, as well as occasional confusion about which concentrations of epinephrine should be injected in which manner (subcutaneously or intravenously).
Dr. Cohan suggested that radiology teams regularly review recommendations and plans for managing allergic reactions to contrast material,
We hope that after reading our study, radiologists, nurses, and technologists will agree that they must review the algorithms for treating contrast reactions on a regular basis (particularly issues related to diphenhydramine, oxygen, and epinephrine administration. In fact, we would suggest that such a review should probably occur at least twice a year. However, it is also consoling to know that even when patients have moderate or severe contrast reactions, the vast majority recover promptly and without any long term complications.
SOURCE: Cohan et al., American Journal of Roentgenology, Volume 91, Issue 2, August 2008.
This news article was originally posted on August 4th, 2008 and was accurate at the time of publication. Since then, information may have changed or links may now be outdated. Please call our Answer Line 1-877-427-2111 for the latest information, or talk to your doctor before making any medical decisions.
Posted by Kate Murphy on August 4th, 2008
Tags: diagnosis, side effects
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Deborah Kanter
August 12, 2008 at 9:03pm
Allergic reactions to contrast is an important consideration when administering the contrast! I learned from a horrible experience with CT scan contrast early in my cancer treatment. Unfortunately, the antidote to the contrast allergy (Medrol) also provoked allergic reactions and I spent the day miserably uncomfortable, itching, and short of breath.
Later, a nurse asked me if anyone asked if I was iodine allergic. If I was asked, and an alternative contrast was administered, this horrible reaction might have been alleviated.
Shari
May 21, 2009 at 10:51am
I had a CT scan on Tuesday and my doctors orders were to do the test without the contrast,but they did the contrast anyway. I got numb in the mouth and my eyes got swollen within 5 minutes I could not breath my throat was swollen. They called and ambulance to come get me and I was taken to the hospital.It is Thursday and my face is still swollen and I don’t know what to do?
Kate Murphy
May 23, 2009 at 8:16pm
If you still have swelling, call the doctor and ask for additional help. You may need a longer course of steroid treatment.
We are not doctors here at C3, so can’t tell you what treatment you need, but you do need to let the doctors who treated your allergic reaction at the hospital what’s going on.
Kate Murphy
May 23, 2009 at 8:18pm
One more suggestion: if you have an allergy to any food, medication, or IV contrast, be sure that the facility where you are being treated puts an wrist band indicating allergy on when you first get there.
Don’t take it off and point it out to anyone who tries to give you something that you are allergic to. Don’t be shy in just refusing!
Mike Dietel
March 8, 2010 at 7:41pm
Heart CT Scan with contrast caused severe anal pain internally as high up as my belly button,and when I went home there were BLISTERS and BURNING AT THE ANAL OPENING.The surrounding tissue was bright RED and painful. Doctor replied ” I’m a Heart guy not a GP go to the emergency room.”