Some patients will have an allergic reaction after having an enhanced CT scan, which may be itchy in mild cases or even life-threatening in severe cases. Common allergies include cough, dry throat, itching all over the body, hives, body erythema, and even difficulty breathing and edema of the throat. Some patients may experience hypotension, shock, and other states. However, any allergic reactions will have corresponding treatment plans, so patients do not need to be overly anxious and worried.