University of Wisconsin–Madison

Contrast Reactions and Pre-Medication

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Prophylaxis Guidelines for Contrast Allergies     

Pre-medication Policy for Patients Receiving Chronic Corticosteroid Therapy

EpiPen Tutorial     

Prophylaxis Guidelines for Contrast Allergies

What type of adverse contrast reaction did the patient experience?

Type of Adverse Contrast ReactionRecommended Response
Non-allergic ReactionNo prophylaxis required.
Immediate Hypersensitivity ReactionProphylaxis contingent upon severity of reaction.
(See Algorithm for next steps)
Unknown ReactionProphylaxis contingent upon date of reaction and type of contrast used.
(See Algorithm for next steps)
Delayed Hypersensitivity ReactionReactions that occur 1 hour or later post injection.
Prophylaxis and performance of CT contingent on reaction details.
(See Algorithm for next steps)

Non-Allergic Reaction Severity Definitions

Mild

  • Isolated self-resolving nausea/vomiting
  • Transient flushing, warmth, chills
  • Headache, dizziness, anxiety, altered taste
  • Mild hypertension
  • Vasovagal reaction that resolves spontaneously

Moderate

  • Protracted but isolated nausea or vomiting
  • Hypertensive urgency
  • Isolated chest pain
  • Vasovagal reactions that require and are responsive to treatment

Severe

  • Arrhythmias
  • Convulsions or seizures
  • Hypertensive emergencies
  • Vasovagal reaction resistant to treatment

No prophylaxis required for any severity level.

Hypersensitivity Reaction Severity Definitions

Mild

  • Localized itching or hives (less than 50% body surface area)
  • Itchy or scratchy throat
  • Nasal congestion, sneezing, redness around eyes, runny nose

Moderate

  • Diffuse hives (rapidly spreading/greater than 50% body surface area)
  • Facial angioedema, throat tightness/hoarseness without stridor
  • Wheezing, bronchospasm without hypoxia

Severe

  • Reaction involving 2 or more moderate symptoms
  • Anaphylaxis
  • Facial angioedema with shortness of breath
  • Throat tightness/hoarseness with stridor, (laryngeal edema)
  • Wheezing, bronchospasm with hypoxia
  • Low blood pressure
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CT Iodinated Contrast Media (ICM) Prophylaxis Algorithm

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  • Patient may receive contrast without medication.
  • Allergy label can be removed from health record by either:
    • Ordering provider/radiologist
    • Radiology RN (after consulting with radiologist)

Mild

  1. Premedication not needed
  2. Do we know what agent caused the reaction?
    • Yes – Switch to different ICM (e.g., iohexol to iodixanol).
    • No – Use the ICM indicated per protocol.

Moderate

  1. Premedication with steroid prophylaxis indicated
  2. Do we know what agent caused the reaction?
    • Yes – Switch to different ICM (e.g., iohexol to iodixanol).
      No – Use the ICM indicated per protocol.

Severe

  1. Radiologist to assess alternative options
  2. If no alternative study can be done, patient will need premedication with steroid prophylaxis. Study should be performed in a hospital setting with a rapid response team available.
    • Proceed – Switch to different ICM (e.g., iohexol to iodixanol).
    • Do not proceed – Consult with allergists to get skin testing with iohexol/iodixanol. If patient is negative to at least one ICM, patient can get the negative-tested ICM with steroid prophylaxis.

  1. Unknown reaction before 1985, then patient can receive ICM without premedication
  2. Unknown reaction 1985 and after, then follow recommendations for moderate immediate hypersensitivity reaction

  1. Symptom onset is greater than one hour post injections.
  2. Did reaction include skin or other organ damage (e.g., blistering)?
    • Yes – Do not give ICM.
    • No – ICM can only be administered after risk/benefit assessment and after patient evaluation by allergy to determine if skin/other testing should be performed.

MR Gadolinium-Based Contrast Agent (GBCA) Prophylaxis Algorithm

|

  1. Patient may receive contrast without medication.
  2. Allergy label can be removed from health record by either:
    • Ordering provider/radiologist
    • Radiology RN (after consulting with radiologist)

Mild

  1. Premedication not needed
  2. Do we know what agent caused the reaction?
    • Yes – Switch to different GBCA (if alternative GBCA is available).
    • No – Use GBCA indicated in the protocol.

Moderate

  1. Premedication with steroid prophylaxis indicated
  2. Do we know what agent caused the reaction?
    • Yes – Switch to different GBCA (if alternative GBCA is available).
    • No – Use GBCA indicated in the protocol.

Severe

  1. Radiologist to assess alternative options:
    • Non-contrast MR
    • Non-GBCA MR (ferumoxytol)
    • Other imaging modalities
  2. If no alternative study can be done, patient will need premedication with steroid prophylaxis. Study should be performed in a hospital setting with a rapid response team available.
    • Proceed – Switch to different GBCA (if alternative GBCA is available).
    • Do no proceed – Consult with allergist to get skin testing with alternative GBCA. IF patient is negative to at least one GBCA, patient can get the negative-tested GBCA with steroid prophylaxis.

  1. Based on available information, can a severe or delayed reaction be ruled out?
    • Yes – Patient can receive GBCA without premedication.
    • No – Follow recommendations for moderate immediate hypersensitivity reaction.

  1. Symptom onset is greater than one hour post injection.
  2. Did reaction include skin or other organ damage (e.g., blistering)?
    • Yes – Do not give GBCA.
    • No – ICM can only be administered after risk/benefit assessment and after patient evaluation by allergy to determine if skin/other testing should be performed.

Resources

  1. UW Contrast Prophylaxis Quick Guide
  2. UW Radiology Contrast Prophylaxis Guidelines

Updated June 2026

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Pre-medication Policy for Patients Receiving Chronic Corticosteroid Therapy

Purpose

This document provides guidance for technologists and physicians managing patients who require corticosteroid premedication for a prior contrast allergy and who are already receiving corticosteroid therapy for another clinical indication.

This guidance is based on recommendations from the American College of Radiology (ACR) Manual on Contrast Media and supporting endocrine literature. Clinical management should be individualized based on patient-specific factors.

Background

The ACR Manual on Contrast Media provides general guidance for premedication in patients receiving chronic corticosteroid therapy. While the manual notes that premedication dosing “may be modified” in these patients, there is limited evidence supporting specific dosing adjustments.

General Principles:

  • Patients receiving only Physiologic (Replacement) corticosteroid dosing generally do not require adjustment to standard premedication dosing.
  • Patients already receiving Supraphysiologic (Therapeutic) corticosteroid dosing may require adjustment of the standard premedication regimen.

Corticosteroid Dose Categories

Approximate Physiologic Daily Dose
Corticosteroid		Approximate Physiologic Daily Dose
Hydrocortisone15–25 mg/day
Prednisone / Prednisolone4–6 mg/day
Methylprednisolone3–5 mg/day
Dexamethasone0.25–0.5 mg/day
  • Supraphysiologic (Therapeutic) Corticosteroid Dosing
    • Any corticosteroid dose above physiologic replacement levels is considered therapeutic or supraphysiologic dosing.

Guidance for Premedication Adjustment

Patients on Physiologic (Replacement) Dose Steroids

(Doses equal to or below hydrocortisone 15-25 mg per day, or equivalent)

  • No dose adjustments to premedication corticosteroids are made

Patients on Supraphysiologic (Therapeutic) Dose Steroids

(Doses equal to or below hydrocortisone 15-25 mg per day, or equivalent)

  • Providers may consider reducing the total premedication corticosteroid dose by an
    amount equivalent to the patient’s baseline daily corticosteroid dose.
  • Adjustments should be individualized based on clinical judgment, patient condition,
    and risk assessment.

Delayed Imaging

If imaging is delayed after initiation of corticosteroid premedication:

  • Patients should ideally receive at least 4–5 hours of corticosteroid therapy prior to contrast administration.
  • Repeat corticosteroid doses may be administered every 4–8 hours until contrast exposure, when clinically appropriate.

Resources

  1. Abe S, Fukuda H, Tobe K, Ibukuro K. Protective effect against repeat adverse reactions to iodinated contrast medium: Premedication vs. changing the contrast medium. Eur Radiol. 2016;26(7):2148-2154. doi:10.1007/s00330-015-4028-1
  2. Beuschlein F, Else T, Bancos I, et al. European Society of Endocrinology and Endocrine Society Joint Clinical Guideline: Diagnosis and Therapy of Glucocorticoid-induced Adrenal Insufficiency. J Clin Endocrinol Metab. 2024;109(7):1657-1683. doi:10.1210/clinem/dgae250
  3. Husebye ES, Pearce SH, Krone NP, Kämpe O. Adrenal insufficiency. Lancet. 2021;397(10274):613-629. doi:10.1016/S0140-6736(21)00136-7
  4. Park HJ, Park JW, Yang MS, et al. Re-exposure to low osmolar iodinated contrast media in patients with prior moderate-to-severe hypersensitivity reactions: A multicentre retrospective cohort study. Eur Radiol. 2017;27(7):2886-2893. doi:10.1007/s00330-016-4682-y
  5. ACR Manual on Contrast Media. American College of Radiology. Updated 2025. Accessed March 31, 2026. https://www.acr.org/clinical-resources/clinical-tools-andreference/contrast-manual.

Updated April 2026

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EpiPen Tutorial – Giuseppe Toia, MD

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