Food Allergy In Infants And Toddlers

Objective: To estimate the prevalence and clinical features of food allergy in children.Methods: From January 1st to February 28th, 2009, all well-infants and young children between the age of 0-3 years attending routine health visits at the Department of Primary Child Care, Children's Hospital, Chongqing Medical University were invited to participate the study. Parents completed questionnaires and all children were skin prick tested 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 should undergo the suspected food elimination and oral food challenge under medical supervision. The factors were studied with Logistic regression analysis.Results: Six hundred and three children were recruited by the consent of their parents. Of 603 children approached, 572 (94.9%) fulfilled the study criteria for diagnosing food allergy, 90 children had positive result in SPT, and 119 (19.7%, 119/603) underwent elimination and food challenges, with 31 subjects dropping out during this procedure. 40 children were confirmed to have challenge-proven food allergy. The prevalence of food allergy in 0-3y children in Chongqing was 7.0% (40/572, 95% CI, 5.2%-9.4%). Assuming that the opportunity of confirmed food allergy was equal among the participants and dropouts, the prevalence was adjusted to 9.2% (95% CI, 6.8%-11.6%). The prevalence of food allergy in children aged 0-1 year was 4.0%-5.2%, and in children aged 0-2years was 7.2%-9.3%, with no increase since 1999. Egg and cow's milk were the most common allergens.Conclusion: 1.The prevalence of food allergy in 0-3years old children in Chongqing, China was 7.0%-9.2%. 2. The prevalence of food allergy in children in Chongqing has not increased since 1999. 3. Egg and cow's milk were the most common allergens in infants and young children.Part 2 the role of skin prick test in diagnosing food allergy in childrenObjective: To study the role of SPT in diagnosing food allergy in children.Methods: From January 1st to February 28th, 2009, all well-infants and young children between the age of 0-3 years attending routine health visits at the Department of Primary Child Care, Children's Hospital, Chongqing Medical University were invited to participate the study. Parents completed questionnaires and all children were skin prick tested. Food allergy was confirmed by oral food challenge.Results: In total, 603 children were recruited and skin prick tested with 31 cases dropping out. Of the 572 who fulfilled the diagnostic procedure, 90(11%) of them had positive results of SPT. At last, 40 children were confirmed food allergy by oral food challenge test. The PPV, NPV, sensitivity and specificity for SPT was 54%, 98.8%, 85% and 94.5% respectively. Among the children who were ruled out food allergy, 10 of them had SPT wheals for egg≥5mm, and one had a wheal for cow'milk≥6mm.Conclusions: 1. With a great specificity, a negative result of SPT had better predictive value than a positive one. 2. Individual medical establishment should develop their own cut-off values in diagnosing food allergy with SPT.