Avaliação clínico-laboratorial do uso da tartrazina em pacientes atópicos: amostra ampliada

Abstract

Yellow tartrazine coloring agent, FD & C Yellow No. 5 or E 102, is an approved azo pigment used in many drugs and foods, improving their appearance, standardizing their color, as well as increasing their visual acceptance and marketing. Since the 70 s many cases of sensibility to tartrazine have been reported, and scientists estimated that approximately 0.6 to 2.9% of the population is affected by this substance, with a higher incidence in atopic individuals or in those with intolerance to salicylates. The colorant sensibility generally consists in asthma and hives, and frequently in contact dermatitis and cutaneous vasculitis. The allergic reaction can be diagnosed with the use of two different techniques: cutaneous test (direct technique) and radioalergos orbent test - RAST (indirect technique). The aim of this study was to evaluate the safety of tartrazine in an enhanced population sampling. The method was double-blinded and controlled by a placebo (DCCP); 77 individuals finished the test, which consisted in two steps. In one of them the individuals were exposed to tartrazine (5 mg, 10 mg, 20 mg) and in the other one they were exposed to placebo (5 mg, 10 mg, 20 mg) with an interval of 50 minutes between each dose. Some clinical parameters presented significant alterations related to the exposure to the coloring agent, such as reduction of the respiratory peak flow, angioedema, nasal congestion, runny nose, wheezing, rash, cutaneous pruride and hives. Nearly 5% of the individuals also presented an increase in the tartrazine IgE levels. While the measurements of arterial blood pressure, heart and respiratory rate, axillary temperature, sneeze/nose itch and cough did not present significant differences between the exposure group and the placebo. The results suggest that in a possible allergic reaction induced by tartrazine there is participation of the immune system and that this reaction is mainly manifested through skin and airways signals and symptoms.