The general characteristics of acute urticaria attacks and the factors predictive of progression to chronic urticaria.

BACKGROUND The natural history of progression from acute urticaria (AU) to chronic urticaria (CU) remains poorly understood. This study aimed to investigate the potential triggers of AU attacks and factors associated with their duration, as well as the factors which may be predictive of progression to CU. METHODS The study included 281 AU patients (AU group). Data were obtained from 207 AU patients retrospectively and from 74 AU patients prospectively. The CU group consisted of 953 patients, whose data were previously published. RESULTS According to the medical history, the most common potential triggers of AU attacks were drugs (38.1%); infections (35.2%); stress (24.7%); and foods (17.8%). Attack duration was shorter in cases in which food (p=0.04) or infection (p=0.04) was the suspected trigger. Patients with a history of rhinitis (p=0.04) and food allergy (p=0.04), and positive skin prick test results for pollens (p=0.02) and dog (p=0.02) also had attacks of shorter duration. Patients with asthma had attacks of longer duration (p=0.01). Based on history and/or provocation test results, the prevalence of non-steroidal anti-inflammatory drug hypersensitivity (NSAIDH) was significantly higher in the CU group than the AU group (24.9% vs. 4.3%, respectively, (p<0.01)), as was antibiotic hypersensitivity (10.6% vs. 4.6%, respectively, (p<0.01)) and food allergy (18.3% vs. 3.9%, respectively, (p<0.01)). NSAIDH (OR 7.97; 95%CI: 4.33-14.66; p<0.01) and food allergy (OR: 5.17; 95%CI: 2.71-9.85; p<0.01) were observed to be independent factors associated with CU. CONCLUSIONS As NSAIDH and food allergy were associated with CU, their presence should be carefully evaluated in patients with AU in order to predict progression to CU.