Allergy to Radiocontrast Dye.

Radiocontrast media (RCM) are common elicitors of immediate and nonimmediate hypersensitivity reactions, manifesting predominantly as urticaria/anaphylaxis or exanthems, respectively. In the minority of patients with immediate hypersensitivity reactions to RCM allergy is demonstrated by positive skin tests. However, data show that assessment by an allergist/immunologist is beneficial for managing patients with previous immediate and nonimmediate hypersensitivity reactions. For future RCM-enhanced examinations in patients with previous reactions, structurally different, skin test-negative preparations should be applied. The efficacy of this strategy is confirmed by drug provocation tests or exposures confirming or excluding RCM hypersensitivity and demonstrating tolerability of alternative RCM.