Chronic urticaria (CU) is defined as the occurrence of spontaneous wheals for a duration of more than 6 weeks and is the most frequent skin disease, with prevalence ranging between 15 and 25%, and is a seriously disabling condition, with social isolation and mood changes causing a significant degree of dysfunction and quality of life impairment to many patients. The main clinical features of CU are the repeated occurrence of transient eruptions of pruritic wheals or patchy erythema on the skin that last less than 24 hours and disappear without sequelae. CU is often defined as Chronic idiopathic urticaria (CIU) because the causes of CU remain unknown in the great majority (70-95%) of patients. Drugs, food, viruses, alimentary conservative substances or inhalant substances often seem to be involved in determining CIU skin flare. Despite a general agreement that bacteria infections and parasitic infestations can be involved in the pathogenesis of CIU, proven evidence of these relationships is lacking. The aim of the present study is to evaluate the prevalence ofHelicobacter pylori (Hp) infection, and the extension and severity of gastritis in a group of CIU patients compared to controls and to evaluate the effectiveness of eradication of Hp on the CIU symptomatology, and the role of Hp infection in pathogenesis of CIU. Copyright © by BIOLIFE, s.a.s.