Asia is a populous and diverse region and potentially an important source of information on food allergy. This review aims to summarize the current literature on food allergy from this region, comparing it with western populations. A PubMed search using strategies "Food allergy AND Asia", "Food anaphylaxis AND Asia", and "Food allergy AND each Asian country" was made. Overall, 53 articles, published between 2005 and 2012, mainly written in English were reviewed. The overall prevalence of food allergy in Asia is somewhat comparable to the West. However, the types of food allergy differ in order of relevance. Shellfish is the most common food allergen from Asia, in part due to the abundance of seafood in this region. It is unique as symptoms vary widely from oral symptoms to anaphylaxis for the same individual. Data suggest that house dust mite tropomysin may be a primary sensitizer. In contrast, peanut prevalence in Asia is extremely low compared to the West for reasons not yet understood. Among young children and infants, egg and cow's milk allergy are the two most common food allergies, with prevalence data comparable to western populations. Differences also exist within Asia. Wheat allergy, though uncommon in most Asian countries, is the most common cause of anaphylaxis in Japan and Korea, and is increasing in Thailand. Current food allergy data from Asia highlights important differences between East and West, and within the Asian region. Further work is needed to provide insight on the environmental risk factors accounting for these differences.

Allergic diseases are on the rise in Asia. Aeroallergen exposure is a strong risk factor for sensitization, development and severity of atopic diseases, especially in the Asian paediatric population. Geographical and seasonal variations in aeroallergen sensitization are seen even within Asian countries and changes in aeroallergen sensitization patterns have been observed over time. Some possible reasons include climate change as well as rapid urbanization and improved sanitation which follow socioeconomic development. House dust mite allergy is present in up to 90% of Asian atopic patients, far exceeding that which is seen in Western populations which report prevalences of only 50% to 70%. Pollen and animal dander affect less than 10% of Asian patients as compared to 40-70% of individuals with asthma and allergic rhinitis living in the West, a burden almost equivalent to the dust mite burden in those regions. There is thus a pressing need for preventive measures to reduce dust mite sensitization in Asian children today.

R ev iew A r tic le 244 I NTRO D U C TIO NSingapore has rapidly evolved into a modernised city state and currently faces the health burden of noncommunicable diseases (NCDs), resembling that of developed Western nations.(1) In children, allergic diseases, including food allergy, are among the most common NCDs.(2) Food allergy rates are reported to be more than 10% in challenge-proven studies among Australian infants, (3) while in the United Kingdom (UK) (4) and the United States of America (USA), Singapore have not met the expected rise experienced by other highly industrialised countries, it is also uncertain whether the food allergy epidemic will hit our nation. This unclear prediction, together with ever-changing cultural practices and eating habits due to immigration and overseas influence, has opened a new chapter of food allergy in Singapore.A PubMed search of the terms "food allergy" and "Singapore" generated a total of 45 results from January 1999 to January 2014. All the articles generated are in English. Of these, 12 articles are not food-allergy focused, and two are focused on food testing methodology that is not unique to Singapore. Of the remaining 31 articles found, 16 are studies conducted on children, and 9 are review articles on food allergy in Asia or Singapore. EPID EM IO LO GYIn Asia, food allergy data is just beginning to emerge, providing no satisfactory trend. One study from Chongqing, China, reported a doubling in the challenge-proven prevalence rates from 3.5% to 7.7% among 0-2-year-olds over a ten-year period. (8) Conversely, a South Korean study reported that the prevalence of food allergy symptoms in 6-12-year-olds had decreased from 10.9% to 8.9% over five years.(9) Preliminary findings in an ongoing study of young Singaporean children aged 11-30 months demonstrated that overall, self-reported food allergy prevalence could be as high as 5.4% (Lee AJ, unpublished). Unfortunately, the only prior data for comparison was in 6-12-year-olds, where the rates (also by questionnaire) were estimated to be 4%-5% in 1999.Given that the prevalence of food allergy tends to decrease with age, using this data, we surmise that food allergy has probably not increased in Singapore over a 14-year period. SPECIFIC FOOD ALLERGIES IN SINGAPOREWorldwide and regional differences in food allergies mainly depend on diet and culture (although this may not always be the case). For example, shellfish is the most common food allergen in Singapore and is ubiquitous in Southeast Asia, likely by virtue of its high consumption. However, fish, also eaten abundantly in Singapore, is a rare allergen here. Allergy to egg and cow's milk, despite their high consumption worldwide, is comparatively lower in Singapore than in the West. The reverse is true of peanut allergy, which is epidemic in the West compared to Asia. However, the pattern of food allergy in Singapore appears to have changed over the last decade, with peanut allergy increasing in prevalence and being the most common cause of anaphylaxis in Singaporean childr...