Management of chronic idiopathic urticaria by the identification and exclusion of dietary factors.

The role played by dietary chemical factors in the pathogenesis of chronic idiopathic urticaria (CIU) was assessed in seventy-six patients by challenge Stable remission was first established by using an empirically established 'exclusion diet'. A diet modified to exclude those chemicals giving a positive response to challlenge was demonstrated to be of therapeutic value for time periods of up to 18 months. Re-testing twelve patients at 12 months indicated that most patients positive to salicylate or benzoate challenge retained this pattern of reactivity.