Epidemiology of urticaria: a representative cross-sectional population survey

Aim. To investigate the prevalence of urticaria with a focus on chronic urticaria (CU) in a general German population. Methods. A questionnaire survey was sent to a representative cross-sectional sample of 13 300 inhabitants of Berlin, Germany, of whom 4093 responded. All respondents who stated ever having had weals or angio-oedema (n = 767) were interviewed by telephone. Any interviewees with recent symptoms (within the previous 3 years) were invited for personal investigation including allergy tests; double-blind, placebo-controlled food challenge tests; and quality of life (QOL) assessment. Reported prevalence rates were weighted with regard to age, gender and education so that they were representative of the total population of Berlin. Results. Lifetime prevalence rate of urticaria was 8.8% (95% CI 7.9-9.7%) for all types of urticaria. Lifetime prevalence for CU was 1.8% (95% CI 1.4-2.3%), and prevalence for the 12 months before assessment was 0.8% (95% CI 0.6-1.1%), and 70.3% were female. QOL was markedly reduced for people with CU. Unlike other allergic diseases, there was no increased risk associated with higher education or social status. Prick tests found sensitization of >= 1 for type 1 allergens in 39.1% of patients. These were related to comorbidities such as allergic rhinitis or oral allergy syndrome, but were never the underlying cause of CU, as proven by double-blind, placebo-controlled provocation tests. Conclusion. Urticaria is a common disease with marked effects on QOL. The lifetime prevalence of 8.8% for urticaria must be regarded as a lower limit as it is based on conservative prevalence rate calculations, and under-reporting of previous disease can be expected in a questionnaire-based study.