Which risk factor carries the highest increased risk for adverse contrast reactions?

Which risk factor carries the highest increased risk for adverse contrast reactions?

• A. Asthma – increased risk by a factor of six
• B. Previous contrast reaction – increased risk by a factor of 10
• C. Atopy – increased risk by a factor of 3
• D. Renal problems – check eGFR

Answer: (B)

A history of a previous adverse reaction to iodinated contrast is the strongest predictor of experiencing another reaction. This prior reaction indicates a predisposition to hypersensitivity on re-exposure, and it increases the risk by about tenfold. Other factors raise risk too, but to a lesser extent: asthma adds roughly sixfold risk, reflecting increased airway reactivity during a reaction, and atopy adds about threefold risk due to a general tendency toward allergic responses. Renal problems and checking eGFR relate more to the risk of contrast-induced nephropathy rather than to acute adverse reactions, so they’re important for overall safety and dosing decisions but do not indicate the same level of risk for immediate contrast reactions.

A history of a previous adverse reaction to iodinated contrast is the strongest predictor of experiencing another reaction. This prior reaction indicates a predisposition to hypersensitivity on re-exposure, and it increases the risk by about tenfold. Other factors raise risk too, but to a lesser extent: asthma adds roughly sixfold risk, reflecting increased airway reactivity during a reaction, and atopy adds about threefold risk due to a general tendency toward allergic responses. Renal problems and checking eGFR relate more to the risk of contrast-induced nephropathy rather than to acute adverse reactions, so they’re important for overall safety and dosing decisions but do not indicate the same level of risk for immediate contrast reactions.