IGHE and allergic disease: While the potential role of immediate hypersensitivity in the pathogenesis of CSU has been considered in only a few reports, current guidelines state that “rarely, IgE-mediated reactions from foods, drugs, or other allergens might result in CSU” and that “Immediate hypersensitivity skin or serologic testing for food or other allergens is rarely useful and not recommended on a routine basis.” [2] SPT is not felt to be relevant, as international guidelines state “Type I allergy is an extremely rare cause of CSU” [5].