What are the guidelines for radiocontrast allergies?

Major Recommendations

Radiocontrast Media (RCM)

  • Anaphylactoid reactions occur in approximately 1% to 3% of patients who receive ionic RCM and less than 0.5% of patients who receive nonionic RCM.(C)
  • Risk factors for anaphylactoid reactions to RCM include female sex, atopy, concomitant use of β-blocking drugs, and a history of previous reactions to RCM.(C)
  • Although asthma is associated with an increased risk of a RCM reaction, specific sensitivity to seafood (which is mediated by IgE directed to proteins) does not further increase this risk. There is no evidence that sensitivity to iodine predisposes patients to RCM reactions.(C)
  • Patients who experienced previous anaphylactoid reactions to RCM should receive nonionic, iso-osmolar agents and be treated with a premedication regimen, including systemic corticosteroids and histamine1 receptor antihistamines; this will significantly reduce, but not eliminate, the risk of anaphylactoid reaction with re-exposure to contrast material.(D)
  • Delayed reactions to RCM, defined as reactions occurring 1 hour to 1 week after administration, occur in approximately 2% [of] patients.(C) Most are mild, self-limited cutaneous eruptions that appear to be T-cell mediated, although more serious reactions, such as Stevens-Johnson syndrome, TEN, and DRESS syndrome have been described.

Rating Scheme for the Strength of the Recommendations

Strength of Recommendation

  • A Directly based on category I evidence
  • B Directly based on category II evidence or extrapolated from category I evidence
  • C Directly based on category III evidence or extrapolated from category I or II evidence
  • D Directly based on category IV evidence or extrapolated from category I, II, or III evidence
  • E Based on consensus of the Joint Task Force on Practice Parameters


Drug Allergy an Updates Practice Parameter: Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology, and the Joint Council of Allergy, Asthma and Immunology; ANNALS OF ALLERGY, ASTHMA & IMMUNOLOGY; VOLUME 105, OCTOBER, 2010