["Chronic idiopathic urticaria (CIU) is defined by the almost daily presence of urticaria for at least 6 weeks without an identifiable cause. Symptoms include short-lived wheals, itching, and erythema. CIU impedes significantly a patient's quality of life (QoL). Levocetirizine is an antihistamine from the latest generation approved for CIU.", 'To investigate the efficacy of levocetirizine, 5 mg, and placebo for the symptoms and signs of CIU, as well as for the QoL and productivity.', 'The primary criteria of evaluation were the pruritus severity scores over 1 week of treatment and over 4 weeks. The QoL was assessed via the Dermatology Life Quality Index (DLQI).', 'Baseline pruritus severity scores were comparable in the two treatment groups (2.06+/-0.58). After 1 week, levocetirizine was superior to placebo and demonstrated a considerable efficacy (difference=0.78, P<0.001). This efficacy was maintained over the entire study period (4 weeks, P<0.001). The number and size of wheals were considerably reduced compared with placebo over 1 week and over the total treatment period (P <or= 0.001). This was paralleled by an improvement in the QoL (DLQI: 7.3 units in the levocetirizine group and 2.4 units in the placebo group) and a higher productivity at work in the levocetirizine group (3.0 workdays lost per patient per month in the placebo group, 0.3 in the levocetirizine group). No unexpected adverse events occurred.'] Is levocetirizine an effective treatment in patients suffering from chronic idiopathic urticaria : a randomized , double-blind , placebo-controlled , parallel , multicenter study?