Supplementary Material for: A Population-Based Study of Fish Allergy in the Philippines, Singapore and Thailand

<b><i>Background:</i></b> Fish allergy is the third most common food allergy after milk and egg in parts of Europe, but there is little data about prevalence in South East Asia where it is an important part of regular diets. <b><i>Objective:</i></b> We aimed to obtain an estimate of the population prevalence of fish allergy among older children in the Philippines, Singapore and Thailand. <b><i>Methods:</i></b> The population prevalence of fish allergy in 14- to 16-year-old children in the 3 countries was evaluated using a structured written questionnaire which was distributed to students of randomly selected secondary schools. An extended questionnaire to determine convincing fish allergy on the basis of typical clinical manifestations within 2 h of ingestion was administered to those with positive responses. <b><i>Results:</i></b> From acohort of 25,842 students, responses were 81.1% in the Philippines (n = 11,434), 67.9% in Singapore (n = 6,498) and 80.2% (n = 2,034) in Thailand. Using criteria for convincing food allergy, fish allergy was much higher in the Philippines [2.29%, 95% confidence interval (CI) 2.02–2.56] than in Singapore (0.26%, 95% CI 0.14–0.79) and Thailand (0.29%, 95% CI 0.06–0.52). Weighted multiple logistic regression analyses showed that compared to the Philippines, prevalence rates were lower in Singapore [odds ratio (OR) 0.40, 95% CI 0.27–0.60, p &lt; 0.0001] and Thailand (OR 0.13, 95% CI 0.05–0.33, p &lt; 0.0001). Females were more likely to have fish allergy compared to males for all children combined (OR 1.32, 95% CI 1.11–1.58, p = 0.002). Most allergies appeared mild, as only 28% of cases sought medical consultation at the time of the reaction and 31.2% of cases reported continued exposure despite allergic symptoms. <b><i>Conclusion:</i></b> Fish allergy in late childhood is more common in the Philippines compared to Singapore and Thailand. Differences in food processing, dietary habits and other cultural practices might be important risk factors for the development of fish allergy in these populations.

**背景**：在欧洲部分地区，鱼类过敏是仅次于牛奶和鸡蛋的第三大常见食物过敏症，但东南亚地区的相关流行率数据却极为匮乏，而鱼类正是该地区日常饮食的重要组成部分。
**研究目标**：本研究旨在估算菲律宾、新加坡及泰国年长儿童的鱼类过敏人群流行率。
**研究方法**：本研究针对上述3国的14~16岁儿童，向随机抽取的中学学生发放结构化书面问卷，以评估鱼类过敏的人群流行率。对于问卷初筛阳性的受试者，研究人员施测拓展版问卷，依据进食后2小时内出现的典型临床表现，判定其是否存在确诊性鱼类过敏反应。
**研究结果**：本研究队列共计纳入25842名学生，菲律宾的问卷回收率为81.1%（n=11434），新加坡为67.9%（n=6498），泰国为80.2%（n=2034）。依据确诊性鱼类过敏的判定标准，菲律宾的鱼类过敏患病率显著高于新加坡与泰国：菲律宾为2.29%，95%置信区间（CI）为2.02~2.56；新加坡为0.26%（95%CI 0.14~0.79），泰国为0.29%（95%CI 0.06~0.52）。加权多因素logistic回归分析显示，相较于菲律宾，新加坡与泰国的鱼类过敏患病率更低：新加坡的优势比（OR）为0.40，95%CI 0.27~0.60，p<0.0001；泰国的OR为0.13，95%CI 0.05~0.33，p<0.0001。合并所有受试儿童的数据后分析显示，女性罹患鱼类过敏的风险高于男性（OR=1.32，95%CI 1.11~1.58，p=0.002）。多数过敏反应症状轻微：仅28%的过敏病例在发作时就医，且31.2%的病例在出现过敏症状后仍持续接触鱼类食物。
**结论**：儿童晚期的鱼类过敏在菲律宾的流行率高于新加坡与泰国。食物加工方式、饮食习惯及其他文化习俗的差异，可能是导致这三个人群鱼类过敏发生率不同的重要危险因素。