Allergic reactions to MRI contrast injections can range from an itchy rash or skin reddening to severe facial and airway swelling. Allergic reactions either happen immediately or at some point within the first hour of injection, according to the MCI Diagnostic Center in Oklahoma.
Mild Allergic Reactions
One of 10,000 patients undergoing an MRI contrast injection will experience a mild allergic reaction, according to the MCI Diagnostic Center. And this one individual will likely experience tenderness and/or pain at the injection site. They may also experience a little skin reddening or rash.
Severe Allergic Reactions
The odds are even lower that patients getting MRI contrast injections will experience a severe allergic reaction; however, it is possible. Generally, 1 out of every 100,000 patients can expect to experience this type of reaction. Severe allergic symptoms can include severe swelling in the face, the airways, and/or the mouth. This swelling can also cause difficulty in breathing, which can be life-threatening.
Allergic Reactions and Pregnancy
While there are no known specific allergic reactions due to MRI contrast injections given while pregnant, the MCI Diagnostic Center recommends that pregnant individuals not receive such injections prior to the 24th week of pregnancy unless an emergency demands its administration. This is merely a safety precaution, since the contrast dye can enter the unborn infant’s circulatory system.
Allergic Reaction Risks
Individuals who have experienced a previous allergic reaction due to an X-ray, CT, or MRI scan are at a greater risk for it happening again. In addition, individuals who have any type of drug or food allergy are also at increased risk of allergic reaction to MRI contrast injections.
Other Possible Reactions
While not labeled as allergic reactions, other reactions to the contrast injection of an MRI are also possible. These include headache, nausea, vomiting, and an odd taste in the mouth (which is only temporary). Most reactions of the nonallergic and mild allergic category are only temporary and mild in nature, requiring no treatment.
Allergic Reaction Treatments
If the allergic reaction is severe, immediate medical attention will be needed. This type of serious allergic reaction often warrants the use of another drug in order to counteract the contrast injections affect. In addition, the individual experiencing such a severe reaction as airway blockage will need to be monitored closely after the reaction—and during the treatment phase addressing it.
Allergic Reaction and Death
According to a study conducted by the University of Michigan Health Systems, under the leadership of Dr. Jonathon R. Dillman, of the 78,000 individuals who received an MRI contrast injection during the study, none experienced an allergic reaction that lead to death. And, in fact, 74 percent of the reactions experienced were mild, 19 percent were considered moderate and only 7percent were severe.