Increased allergic sensitization to mugwort in chronic urticaria

Background: Mugwort pollen is known to cross-react with a variety of spices and vegetables that are typically part of elimination diets used in the treatment of chronic urticaria (CU). Objective: We sought to investigate the association between CU and allergic sensitization to mugwort pollen. Methods: We conducted 2 case-control studies comparing aeroallergen skin prick test results between patients with and without CU and with or without allergic rhinitis (total n = 202). Results: CU patients with coexisting allergic rhinitis were more than twice as likely to be sensitized to mugwort as subjects not suffering from CU (67 vs. 30%; p = 0.004). Ragweed, cat, rat and mite sensitization were also significantly associated with CU. Overall, patients with CU had more positive aeroallergen skin tests than patients without CU (p < 0.005). Conclusion: Mugwort sensitization was associated with CU, possibly contributing to beneficial effect of elimination diets.