Designating radiology patients with the imprecise diagnosis “iodine allergy” may be dangerous, as it could lead to unnecessarily unenhanced scans as well as uncertainty in clinical management and sometimes even useless preventative measures.
That’s according to a study conducted by researchers at Bern University Hospital in Switzerland and St. John’s Medical Center in Tulsa, Okla., and published online March 1 in the German radiology journal RöFo.
The team compared case data on 300 patients with a history of generalized “iodine allergy” with data from patients matched for age, sex and procedure and diagnosed with an allergy to either a nonspecific iodine contrast medium (ICM) or a specific ICM agent.
The researchers analyzed and compared all three datasets, noting the clinical symptoms of the most recent past adverse drug reaction (ADR), prophylactic actions taken for subsequent imaging and ultimate outcomes.
They found the diagnosis “iodine allergy” was not otherwise specified in 84.3 percent of the patients. More concerning, the symptoms of the previous ADRs had not been documented for most patients in this group.
By contrast, the type of ADR was undocumented in only a minority of patients in the comparison groups.
Moreover, in the group of patients designated as having a generalized allergy to iodine, the percentage of unenhanced CT scans was greater than within the other two groups (36.7 percent vs. 28.7 percent and 18.6 percent). And ADRs following prophylactic measures were only observed in the “iodine allergy” group.
In their discussion, lead author Ingrid Böhm and colleagues note the problematic nature of using the broad designation “iodine allergy” to guide imaging decisions. They point out that the term fails to distinguish between different substance classes, lumping together, for example, disinfectants with iodine-containing solutions and contrast media containing covalently bound iodine.
“There is a clear correlation between the exactness of the diagnosis—from the alleged ‘iodine allergy’ to ‘contrast media allergy’ to naming the exact culprit contrast medium—and the quality of documentation of the symptoms,” the authors write.
“The term ‘iodine allergy’ should be omitted,” they conclude, “because it is potentially dangerous and can decrease the quality of radiology exams.”
Dave P. has worked in journalism, marketing and public relations for more than 30 years, frequently concentrating on hospitals, healthcare technology and Catholic communications. He has also specialized in fundraising communications, ghostwriting for CEOs of local, national and global charities, nonprofits and foundations.