Subjects recruited into the study will have a 3 month history of CIU and/or Angioedema and will be randomly assigned to either the active or control arm of the study in a single blinded fashion. All subjects will be advised to cease antihistamine medication and will receive one-on-one dietary counselling by a Dietitian. The diet to which each subject has been assigned (ie either active or placebo) is to be followed for a 4 week duration. The frequency and severity of CIU and/or Angioedema as well as adherence to the diet are to be measured on both a daily and weekly basis by the subject via the completion of a clinical score card. The results of the score cards will be collated to determine the relative effects of each diet on these conditions.