Abstract: Objective: To analyze the risk factors of acute spontaneous urticaria (ASU) developing into chronic spontaneous urticaria (CSU) in 178 patients. Methods: The data of 178 patients with ASU in Weifang People's Hospital from November 2018 to October 2019 was analyzed, including age, sex, first onset season and duration, self-report of suspected allergens, autologous serum skin test (ASST), urticaria activity score 7 (UAS7), blood routine test, serum total IgE level and therapeutic drugs. Results: Of 178 patients with ASU, 42 (23.60%) developed into CSU. The univariate analysis showed food allergy (P<0.001), positivity for ASST (P<0.001) and long first onset duration (P<0.001) were associated with ASU developing into CSU. Logistic regression analysis showed that food allergy (P=0.029), positivity ASST result (P<0.043) and long first onset duration (P<0.001) were risk factors for ASU developing into CSU. Conclusion: Food allergy, positivity for ASST and long first onset duration are the risk factors for ASU developing into CSU.

Key words: acute spontaneous urticaria, chronic spontaneous urticaria, risk factors