Delayed cutaneous reaction — mild

Recognize

• Rash or urticaria appearing 1 h – 1 week post-contrast
• Maculopapular exanthem
• Pruritus with or without urticaria
• Most occur between 3 h and 2 days post-contrast

Act — tap each step

1. 1Usually self-limited — reassure patient
2. 2Antihistamines (Diphenhydramine 25–50 mg PO) for pruritus/urticaria
3. 3Topical corticosteroids for localized rash
4. 4Document reaction for future contrast planning

Medications

Notes

• Delayed reactions occur in 0.5–14% of patients receiving iodinated contrast.
• More common with iso-osmolar dimer iodixanol.
• More common in patients on interleukin-2 (IL-2) therapy.
• Premedication for future studies is NOT specifically advocated for prior mild delayed cutaneous reactions.