- Chronic urticaria (CU) and atopic disorders such as atopic dermatitis (AD), allergic rhinoconjunctivitis (AR), and asthma are related to aberrant immune function. The relationship between atopic disorders and CU is controversial, mostly since epidemiological data are lacking. The aim of our study was to investigate the association between CU and asthma, AD, and AR using a database of Clalit Health Services (CHS) - the largest healthcare provider organization in Israel. This article is protected by copyright. All rights reserved.