April 20, 2011 by dailybolusoflr
Is this such a thing as an “iodine” allergy?
· Many patients will tell you that they have an iodine allergy due to an allergic reaction to shellfish. This is a misconception. Iodine is naturally occurring in our bodies and people cannot be allergic to it. People with allergies to shellfish typically have an allergy to the protein contained in the food, known as tropomysin.
Can patients with shellfish allergies get contrast?
· Patients with shellfish allergies should be considered the same as people with other allergies/atopy (peanuts or medication allergy, asthma, atopic dermatitis). These patients are more likely to have a reaction to contrast material simply by nature of the fact that they are ‘allergic’ people. It has nothing to do with shellfish in particular.
· In general, people with severe allergic reactions have a 2-3 fold increased risk of a reaction to contrast.
What about people with local reactions to betadine?
· Patient with topical sensitivity to povidone-iodine are not at any greater risk than the general population for a reaction to IV contrast.
Katayama et al. Radiology. 1990
Linda Regan, MD FACEP
Program Director, Emergency Medicine Residency
Johns Hopkins Medical Institutions