The prevalence and temporal trends of food allergy among preschool children in Northern Thailand between 2010 and 2019

Abstract

Background: Although recent studies suggest that the prevalence of food allergy (FA) has not changed, the data from developing countries are limited. This study aimed to investigate time trends in the prevalence of FA among preschool children in 2010 and 2019 in Northern Thailand.Methods: Two cross-sectional studies were performed, 9 years apart (2010 and 2019), using the same methods, in children aged 3-7 years living in Chiang Mai, Thailand. Parent-reporting questionnaire surveys were conducted. Families with children reporting FA were invited to undergo further investigations with skin prick testing, serum specific IgE, and oral food challenge (OFC). The prevalence of parent-reported FA, food sensitization, and OFC-confirmed FA were compared between the 2 periods.Results: A total of 1013 out of 1146 questionnaires (452/546 in 2010 and 561/600 in 2019) were returned. The response rate was 88.4%. The prevalence of parent-reported food allergy in 2019 was significantly lower than that in 2010 (5.5% vs 9.3%; p ¼ 0.02). However, there was no significant change in the prevalence of OFC-confirmed FA (0.9% vs 1.1%; p ¼ 0.75). Three leading causative foods of parent-reported FA were cow's milk, shrimp, and eggs. Shrimp was still the most common OFC-confirmed food allergen. Atopic dermatitis was the most significantly parent reported factor associated with FA. Conclusion:The overall prevalence of FA among preschool children in Northern Thailand had not increased during the past decade. There was no significant difference in the prevalence of OFC-confirmed FA between 2010 and 2019.

Birth order, sibship size, and risk of atopic dermatitis, food allergy, and atopy: A systematic review and meta‐analysis

“…On the other hand, a register‐based study on any food allergy diagnosis found no association with birth order ≥2 versus 1 53 . Similarly, Of the two population‐based studies on sibship size and any food allergy, one indicated a lower risk of the outcome in subjects with ≥6 versus <6 siblings, 54 while the other reported no significant association 55 …”

Food allergy in Sri Lanka – A comparative study

“… 16 However, the pattern of food allergy seen in our study has important differences with other Asian countries as well as with Europe and the United States ( Table 5 ). 5 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 …”

Allergic sensitization to foods in India and other Low–Middle‐income countries

“…Jackfruit was uncommonly studied and sensitization to jackfruit on SPT was 2.46% in children from India 9 . One study from Thailand observed self‐reported adverse reactions to insect eggs (Ant) of 0.53% in children 36 (Figure 6).…”

“…40 The highest self-reported adverse reaction to shellfish (24.4%) was observed in China. 32 Self-reported adverse reactions to the most common foods of global relevance in children and adults from India and other LMIC countries from Europe, 13,14 North America, 21,22 South America, 23,24 and Asia 18,19,[25][26][27][28][29][31][32][33][34][35][36][37][38] are presented as a heatmap (Figure 5A).…”

“…The lowest prevalence of Oral Food Challenge (OFC)-confirmed food allergy is seen in China (0.5%) 19,28 and the highest is seen in South Africa (2.5%). 16 The prevalence of oral challenge-confirmed food allergy in other LMICs was <1% in Thailand (0.9%), 36,37 Turkey (0.8), 13 and Brazil (0.61). 23 Probable food allergy was defined in studies as symptoms within 2 h of consumption of the food and either a positive serum-specific IgE or SPT for the same food.…”