Immediate and non-immediate reaction after non-ionic X-ray contrast medium injection: Case report and review of the literature

Maculopapular rush (exanthema) is the most common contrast medium (CM)-induced non-immediate (delayed) reaction, accounting for over 50% of affected patients. In this article, we describe the clinical course of a 50-year-old female patient who underwent CM-enhanced computer tomography (CT). During non-ionic CM-injection (iopromide) she developed dyspnoea and itching. 24 h afterwards the patient presented with generalized small red macules that tended to confluence (maculopapular exanthema) and itching. Because in vivo testing was not possible, we analyzed blood cells by the cellular allergen stimulation test (CAST), and found slightly increased leukotriene production in the presence of iopromide, while another CM (iotrolan) did not induce leukotriene production. In addition we reviewed available literature for CM related maculopapular exanthema. This clinical feature due to CM is a characteristic delayed (non-immediate) reaction that usually occurs 24 h after CM administration and has been preferentially reported due to non-ionic dimeric CM. Laboratory tests like the CAST that are used in parallel with in vivo skin tests would be of great relevance but are currently not validated. As to whether intra-individual reactions with both immediate and delayed symptoms after CM-injection occur seldom or have been only rarely reported is currently unknown.