Time trends of childhood food allergy in China: Three cross‐sectional surveys in 1999, 2009, and 2019

Abstract

Background Many countries have recorded the trends of food allergy (FA) prevalence. Little is known about epidemiologic trends of childhood FA in China. Methods In three cross‐sectional surveys conducted in 1999, 2009, and 2019, the prevalence of and characteristic changes in FA in children aged ≤ 2 years were assessed and the outcomes were compared. All the children were recruited during well‐baby check‐ups at the Children's Hospital of Chongqing Medical University. All participants had a detailed medical history taken and underwent skin prick tests using ten commercial food extracts. Open food challenges were used for confirmation of FA. Results The three studies included 1228 children (314 in 1999, 401 in 2009, and 513 in 2019; response rate > 95%). The prevalence of FA in 2009 (7.7%) and 2019 (11.1%) was significantly higher than that in 1999 (3.5%). However, there was no statistically significant difference in prevalence between 2009 and 2019 (P = .086). There was evidence of increased prevalence in CMPA between 1999 and 2019 (1.6% versus 5.7%; P = .004). However, no statistic difference was found in egg allergy (2.9% versus 5.5%; P = .21). The incidence of skin symptoms did not differ significantly over the study period, while the incidence of gastrointestinal symptoms increased significantly (18.2% in 1999, 12.9% in 2009, and 43.9% in 2019; P < .05). Conclusions The prevalence of FA in children rapidly increased after the 1990s and gradually stabilized after 2010. Cow's milk has become the most common food allergen among children in Chongqing. The incidence of gastrointestinal symptoms as a manifestation of FA has increased significantly since 2010.

Trends in use of specialized formula for managing cow's milk allergy in young children

“…We have assumed that milk allergy overdiagnosis is mainly responsible for this observed increase in the use of specialized formula. It is possible that there has been an increase in milk allergy incidence, as recently reported in one Chinese study 23 . However, epidemiological studies do not suggest any increase in milk allergy in England or Australia in recent decades 12–15 .…”

“…It is possible that there has been an increase in milk allergy incidence, as recently reported in one Chinese study. 23 However, epidemiological studies do not suggest any increase in milk allergy in England or Australia in recent decades. [12][13][14][15] Finally, data are limited to three, high-income countries and trends in specialized formula consumption may differ in other settings -other methodologies may be needed to develop a complete understanding of global patterns of specialized formula use.…”

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

“…[13][14][15][16] Moreover, a repeated cross-sectional study, using the same methodology of OFC-proven outcomes shows that the prevalence of FA in infants from Chongqing, China significantly increased from 3.5% in 1999 to 7.7% in 2009 (p ¼ 0.017), but there was no significant difference found in 2019 (11.1%). 17 In Thailand, 2 studies have reported on the prevalence of FA. The first study 18 published in 2005, surveyed children aged 6 months to 6 years in Bangkok.…”

Editorial comments on: “Worldwide time trends in prevalence of symptoms of rhinoconjunctivitis in children: Global Asthma Network Phase I”

“…Although respiratory allergies and atopic dermatitis continued to rise in the last decades, but mostly in developing countries, the focus in Europe, North America, and Australasia has been more on food allergy, as these have been sharply increasing in these countries 2,3 . In addition, studies were mostly focusing on the development of respiratory diseases in risk populations and cross‐sectional studies were largely lacking 4 …”