Comparison of the efficacy of olopatadine and fexofenadine in chronic idiopathic urticaria patients: a crossover study.

Olopatadine is one of the second-generation H1 antihistamines that were used for treating allergic disorders initially in Asia, and now also in Western countries. Whereas several trials compared the efficacy on chronic urticaria among second-generation H1 antihistamines, no study has directly compared the clinical efficacy between olopatadine and other H1 antihistamines in patients with chronic idiopathic urticaria (CIU). In this study, we address this issue for the first time and conclude that olopatadine is a good candidate for the treatment of CIU.