This page explains what an allergic reaction is and how to care for yourself should this happen.

What is an allergic reaction?

You can have an allergic reaction from contact with different things such as foods, insect stings and medications.

In radiology, allergic reactions can happen after you have been given a medication intended to help with your examination. If you experience an allergic reaction, you may have feelings of nausea (feeling sick) and/or shortness of breath. You may also notice changes in your voice or on your skin such as itchiness, redness or raised bumps called hives. It is important that you follow the advice given to you by the nurse or radiographer and the instructions on this page.


You will have been monitored by a member of the nursing or medical team to assess the reaction you have experienced. In some cases, you may have been given medication to help your body recover from the reaction.

You will be asked to stay in the department until your symptoms have settled. A doctor or nurse may examine you before you leave the department and advise you if any further treatment is necessary.

In rare cases, you may be referred to the Emergency Department for further assessment.

Is there anything I can do at home?

If you have had a reaction at the site of an injection of medication, you are advised to monitor the area for any signs it has come back.

If advised to do so you may take anti-histamine medication. Please follow the instructions provided in the packet. If the area is painful, take your usual pain relief.


If you have any of the following symptoms, you should contact your GP or NHS 111 for advice. Please take the below leaflet with you:

  • Nausea or vomiting up to 24 hours after the reaction.
  • Increased redness, itching, a rash or bumps on your skin.

If you experience shortness of breath, difficulty swallowing or speaking you should go to the Emergency Department.


If you receive further appointments for imaging from any Radiology department, it is important that you let them know about this reaction. Your healthcare professional with advise the medication used.

Contact information

If you have any questions or concerns about your reaction then please contact the Radiology Nursing Team.

Tel: 0300 422 5152 or

Tel: 0300 422 3063

Monday to Friday, 9:00am to 5:00pm

Outside of these hours you should contact NHS 111 for advice.

NHS 111

Tel: 111

Printable version of this page

Allergic reactions for radiology patients GHPI1451_02_24 Department: Radiology Review due: February 2027 PDF, 235.0 KB, 3 pages
Reference number GHPI1451_02_24
Department Radiology
Review due February 2027