Objective      To investigate clinical epidemiological charateristics of chronic urticaria (CU).       Methods      A survey was conducted to clinically diagnosed CU patients in our hospitals from January to September 2010. All these subjects received physical examination by dermatologists and were required to fulfill the self-report questionnaires. EpiData and SPSS 13.0 were utilized for statistical analysis.       Results      Totally

there were 535 valid questionnaires returned in this survey. Of them

204 were male and 331 were female with a mean age of 34.4±14.0. The average age of these subjects at first onset was 30.6±14.8. The prevalence of CU peaked in patients aging from 20 to 40 years. The self-reported eliciting factors of urticaria were as follows: physical stimuli 94 (approximately 17.6%)

drugs 23 (4.3%)

foods 29 (5.4%)

mental factor 39 (7.3%)

working pressure 9 (1.7%)

mosquito 24 (4.5%)

and others 54 (10.0%)

whereas 263 (49.2%) of the participants could not identify any trigger. The most common type was chronic spontaneous urticaria (CSU)

accounting for 294 (55.0%)

followed by dermographic urticaria factitia 120 (22.4%). While the rarest type was delayed pressure urticaria

vibratory urticaria and exercise induced urticaria type. Angioedema in CU accounted for 105 (19.6%)

70 (21.1%) were female

and 76 (25.9%) were CSU with it.  Positive autologous serum skin test (ASST) was accounted for 49.6%.      Conclusion      The high prevalence of CU is in the young populations

with various clinical manifestations. Coexisting with angioedema is not uncommon. Investigating CU clinical epidemiological characteristics is helpful to guide the therapy strategies.