Iodinated contrast media-induced acute generalized exanthematous pustulosis confirmed by delayed skin tests.

on si de re d ne ga tiv e or in tr av en ou s ad m in is tr at io n w ith no re ac tio n. TO THE EDITOR: Although immediate hypersensitivity reactions to iodinated contrast media (ICM) are well recognized, delayed cutaneous reactions (1 hour to 7 days) are much less easily diagnosed. The clinical manifestation usually is moderate, but sometimes serious reactions may occur. To our knowledge, we report the largest series of cutaneous delayed reaction that presented as acute generalized exanthematous pustulosis (AGEP) after ICM administration confirmed by skin testing. Skin tests performed 6 weeks after AGEP included patch tests followed by intradermal tests (IDT). ICMs tested were the same for all patients (ioxaglate, iomeprol, iopamidol, iodixanol, iohexol, iobitridol). Patch tests were conducted with undiluted ICM. Readings were conducted on days 2 and 4. Positive results were considered in accordance with the recommendations of the European Society of Contact Dermatitis. IDTs were performed with 10-fold diluted and undiluted ICM, and readings were conducted after 20 minutes and on day 2. Intravenous administration was performed 1 month later by using an alternative ICM that had negative skin tests and was also selected in consultation with the radiologist based on the ICM needed. The first dose injected was 0.5 mL. Two hours later, if no reaction occurred, then 2 mL was injected. The entire dose was administered only for the radiologic examination. All skin tests and intravenous administrations were conducted in a dermatology hospital unit.