OBJECTIVETo estimate the prevalence and clinical features of food allergy in children aged 0 - 2 years.

METHODFrom January to February, 2009 and January to May, 2010, all well-infants and young children between the age of 0 and 2 years attending routine health visits at the Department of Primary Child Care, in Chongqing, Zhuhai and Hangzhou were invited to participate in the study. Parents completed questionnaires and all children were skin prick tested (SPT) to a panel of 10 foods (egg white, egg yolk, cow's milk, soybean, peanut, wheat, fish, shrimp, orange and carrot). Based on the results of SPT and medical history, the subjects under went the suspected food elimination and oral food challenge under medical supervision. Food allergy was confirmed by the food challenge test.

RESULTTotally 1687 children were recruited by the consent of their parents. Of 1687 children approached, 1604 (550 of Chongqing, 573 of Zhuhai and 481 of Hangzhou) fulfilled the study criteria for diagnosing food allergy. One hundred children were confirmed to have challenge-proven food allergy in 3 cities (40 of Chongqing, 33 of Zhuhai and 27 of Hangzhou). The prevalence of food allergy in 0-2 years old children in Chongqing was 7.3%, in Zhuhai was 5.8% and in Hangzhou was 5.5%. There was no significant difference in the prevalence of food allergy in children under 2 years among the three cities, and the average prevalence for food allergy in children under 2 years was 6.2%. Egg (3.0% - 4.4%) was the most common allergen, followed by cow's milk (0.83% - 3.5%), shrimp (0.17% - 0.42%) and fish (0.17% - 0.21%).

CONCLUSIONThe prevalence of food allergy in 0 - 2 years old children in China was 5.5% - 7.3%. There was no significant difference in the prevalence of food allergy in children under 2 years of age among the three cities. Egg was the most common allergen, followed by cow's milk, shrimp and fish.