Delayed allergy-like reactions to X-ray contrast media: mechanistic considerations.

摘要: Iodinated X-ray contrast media are among the most frequently used pharmaceuticals for intravascular administration. Although newer low osmolality, nonionic media, generally well tolerated, it is known that they, like ionic give rise to immediate or delayed adverse reactions in susceptible individuals. In present review, allergy-like reactions, which by definition occur more than 1 h after medium administration, described, and possible pathophysiological mechanisms discussed. Delayed have been reported 0.5-2% of recipients, mainly mild moderate skin maculopapular exanthematous urticarial/angioedematous types. Most become apparent a latency 3 2 days disappear within week. The incidence severe extremely low. Main risk factors appear be previous reaction, history allergy, IL-2 treatment being Japanese descent. At present, exact pathogenesis these still unclear. There is, however, increasing evidence significant proportion T-cell mediated.