A follow-up study of patients with recurrent urticaria and hypersensitivity to aspirin, benzoates and azo dyes

Abstract

Patients (75) with recurrent urticaria and angio-edema of more than 4 mo. duration, and with positive provocation tests to aspirin, azo dyes and/or benzoates were studied. Cross-reactions between the test compounds were common. The patients were recommended to be on a diet free from salicylates, benzoates and azo dyes. They were then followed for 6-24 mo. At the follow-up, 24% were free from symptoms, 57% considered themselves much better and 19% stated that they were slightly better or unchanged. All patients had followed the diet for at least 1-3 mo. Most of those who became totally free of symptoms did not continue with the diet; most of the patients who considered themselves much better found that it was necessary to continue on the recommended diet. They usually developed symptoms as soon as they ingested something containing azo dyes or benzoates. To be able to maintain such a diet, it is important that the content of additive in food and drugs be properly declared.