The danger of "yellow dyes" (tartrazine) to allergic subjects.

Oral administration of 50 mg tartrazine to 122 patients with a variety of allergic disorders caused the following reactions: general weakness, heatwaves, palpitations, blurred vision, rhinorrhoea, feeling of suffocation, pruritus and urticaria. There was activation of the fibrinolytic pathway as shown by reduction of plasminogen with high pre-kallikrein and low kallikrein values. Reduction in complement activity (CH50) was seen in three out of sixteen reactions.