Objective　To Investigate the pathogenesis of chronic idiopathic urticaria.Methods　Basophil histamine release assay was utilized.Result　15 of 32 cases(46.9%)had increased serum histamine releasing activities. This implied that anti-FcεR1 and anti-IgE autoantibodies existed in the sera of some patients with chronic idiopathic urticaria.Conclusion　It suggested that autoimmunity might take part in the occurrence of some patients with chronic idiopathic urticaria.

Objective To investigate and compare the effect and safety of levocetirizine and cetirizine for the treatment of chronic idiopathetic urticaria (CIU). Methods A multi-center, randomized and double-blind comparative clinical trial was employed. 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. Results One hundred and thirty cases were evaluable for the effect and safety at the end of the study. The effective rates in levocetirizine group and in cetirizine group were 73.44% and 77.27% on the 7th day after treatment, 82.81% and 81.82% on the 14th day, and 89.06% and 81.82% at the end of the therapy respectively. There was no significant difference between the two groups. The drug adverse reaction for levocetirizine group and cetirizine group were 14.06% and 18.18% respectively, which include mouth dryness, dizziness etc. Conclusion Levocetirizine is an effective and safe agent for the treatment of CIU.