Oral food challenges: result of a 16-year experience at a major teaching hospital in Thailand.

BACKGROUND

Prevalence of food allergy is increasing all over the world including in Asia. Diagnosis of food allergy in Asia is usually made after family complaints or by elimination and/or reintroduction foods. This could lead to an inaccurate diagnosis and to incorrect information on epidemiology of food allergy. We, herein, reported results of a 16-year experience (1996-2012) of oral food challenge (OFC) performed in pediatric patients at a major teaching hospital in Thailand.

OBJECTIVE

The major objectives of this report are to review types of foods selected for oral challenges, frequency of positive/negative challenges to these foods and the clinical reactions during challenges among these children.

METHODS

Medical records of 206 children underwent OFC between 1996 and 2012 for various indications at the Allergy clinic of Pediatric Department, Siriraj Hospital, Mahidol University (age range, 4 months to 17 years) were retrospectively reviewed. Data including clinical data, skin prick test results and specific IgE levels were analyzed with respect to challenge results (positive/negative). During the period of the study, 2 separate investigations on shrimp allergy and wheat allergy were conducted.

RESULTS

Sixty of 206 children (29%) had positive OFC, whereas 84 out of 306 OFC (27.5%) were positive. The most common food giving positive challenges in this study was shrimp (40%). Among children less than 3 years of age, the most common food with positive challenge was wheat (70%) whereas among children 3 years of age or older, shellfish was the most common food (42%). Cutaneous reactions were the most common reactions observed.

CONCLUSION

Only 1 out of 3 children underwent OFC in this study had positive challenges. Shrimp was the most common food causing challenge in this study especially among children older than 3 years of age. Wheat has become another leading food besides cow's milk and egg in causing positive OFC in younger children in Thailand.