What should he do? My husband had a cat scan this morning about 7 am. He is allergic to shellfish, so they had him take benedryl a half an hour before the scan. He went to work and around 4 pm he started feeling really warm. He came home and I noticed he

The . The dye used for the ct scan is inorganic and should not cross react because of the shellfish allergy. That does not preclude that he is having or had a reaction to the dye. The doctor who ordered the study and all his physicians should be informed of what happened. He should be seen by an allergist who could better define by the history what is going on.
You . You need to contact the radiologist who read the scan and let them know what is going on. He most likely had a reaction to the dye.