SummaryOral 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 plas‐minogen with high pre‐kallikrein and low kallikrein values. Reduction in complement activity (CH50) was seen in three out of sixteen reacti