Chronic idiopathic urticaria (CIU) is defined as the daily or almost daily occurrence of spontaneous pruritic wheals for at least 6 weeks.1 Although good epidemiological data are lacking, the prevalence in an outpatient dermatology clinic is around 4%.2 Angioedema is associated with CIU in about 40% of cases3 and, although it causes serious distress and disability, is hardly ever fatal. Physical urticarias such as symptomatic dermatographism and delayed pressure urticaria frequently occur concurrently with CIU.
Gil Yosipovitch, Malcolm Greaves. Chronic Idiopathic UrticariaA “Cinderella” Disease With a Negative Impact on Quality of Life and Health Care Costs. Arch Dermatol. 2008;144(1):102–103. doi:10.1001/archdermatol.2007.6