No published information exists about the incidence of
food additives reactions in the general population. Most studies have been made in patients with
urticaria and
bronchial asthma. The majority of them lack an adequate design and, therefore, the reported results should be interpreted with extreme caution. In this article, we expose our ten years experience in this field. We have added up 1941 oral provocation tests, with an ample battery of additives, administering the tested substances directly or in aqueous or
acid solution (1110 in patients with
urticaria, mainly
chronic urticaria, and 831 in asthmatic subjects, with or without
aspirin intolerance). From these exhaustive data, we get the following conclusions: 1) in contrast with other-investigators, and using similar or even higher provocation doses, we get a very low incidence of adverse reactions. 2) We are sceptical that
food additives play any role in
chronic urticaria or in other cutaneous processes (only 0.63% provocation tests resulted in an urticarial exacerbation, and none of them was repeated after re-provocation). 3) In asthmatic patients, similar results were obtained, except with
sulfites in
acid solution challenge test (10% asthmatic exacerbations), possibly as a sign of nonspecific
bronchial hyperreactivity. 4) The prescription of
food additives free restrictive diets does not seem to be justified. The should be followed only by those patients with clear evidence of additives reactions. 5) In most cases, with punctual exceptions, the study of
food additives reactions, in clinical
allergy, implies a waste of time.