Abstract: Objective To investigate the relationship between food intolerance and major adolescent oral ulcer. Methods Eating habits of 45 children with major adolescent oral ulcer were investigated during 2008 and 2014. The levels of IgG against 14 common food were measured by ELISA. Immunology detection was conducted. Another 20 children with minor recurrent oral ulcer were selected as controls. Results Major adolescent oral ulcer often presented in patients aged 6 to 12 years and boys were more vulnerable. The tongue tip and buccal fat pad were the preferred sites. The ulcer was big and deep. The center was in depression surrounded by pale, uplifted tissues. The patients felt severe pain. All children with major adolescent oral ulcer ate unbalanced diet. Total positive rate of serum food-intolerant IgG antibodies was 90.6% and 45% in children with major adolescent oral ulcer and children with minor recurrent oral ulcer. Among these 14 food, the positive rate of egg was the highest, and it was higher in major adolescent oral ulcer than in minor recurrent oral ulcer with statistical significance(P<0.05). The immunity of children with major adolescent oral ulcer was almost normal, and 55.6% children had CD4⁺ T cell lower than normal. The pathology was infiltration of chronic inflammatory cells and the thickening of vessel walls. After diet changes and drug treatment, 44 childrens ulcer was under control, the total effective rate being 97.8%. Conclusion Major adolescent oral ulcer is closely related to food intolerance. Egg and milk are the most common intolerant food. Avoiding the intolerant food and drug treatment show acceptable efficacy in the treatment of most children with major adolescent oral ulcer.

Key words: Major adolescent oral ulcer, Food intolerance, Treatment