The patients with CIU were divided into levocetirizine group and cetirizine group. Levocetirizine (5mg/day) or cetirizine (10mg/day) were taken once daily for 28 days, and were followed up on the 7th day, 14th day and 28th day after starting treatment.

• 试验组盐酸左西替利嗪片每日1次,每次5mg,对照组盐酸西替利嗪片每日1次,每次10mg,均连续服用28d。 分别于用药后第7、14、28天随访,观察疗效和不良反应。