Abstract: Objective: To determine the features of allergen-specific IgE (sIgE) of food in the patients with acute urticaria. Methods: The level of sIgE was measured in the patients with acute urticaria from June 2018 to October 2019 by ELISA. The patients with positive test results for eggs and milk were subjected to oral food challenge (OFC). Results: Four hundred and sixteen patients were collected, of whom 161 patients were positive for sIgE, including 56 with egg allergy and 29 with milk allergy. The positivity rates of the patients with egg sIgE (0.35-0.70 IU/mL) and (0.7-2.0 IU/mL) were 2.8%（1/36）and 81.8%（9/11）respectively. The percentages of the patients with milk sIgE of 0.35-0.70 IU/mL and 0.7-2.0 IU/mL were 0% (0/16) and 37.5% (3/8). Conclusion: Eggs and milk are the most common allergens in patients with acute urticaria. The patients may need not to avoid to eat allergic food when sIgE is less than 0.7 IU/mL. 

Key words: acute urticaria, allergen, specific IgE, oral food challenge, food