November 13, 2023
4 minutes of reading
- The researchers used a standardized methodology to assess global food allergy.
- Among children, prevalence was lowest in Germany and Japan and highest in Canada.
- Among adults, rates were lowest in Japan and highest in Italy.
ANAHEIM, Calif. — ASSESS FA study researchers used a consistent methodology to calculate the symptom-based prevalence of food allergy across countries, finding that rates varied specifically in North America, Europe and Japan.
Because studies reporting the prevalence of food allergies in different countries have used different methodologies, it has been difficult to compare these rates and understand whether differences exist. Ruchi S. Gupta, MD, MPH, professor of pediatrics and medicine and director of the Center for Food Allergy and Asthma Research at Northwestern University Feinberg School of Medicine and Ann and Robert H. Lurie Children’s Hospital of Chicago, said during his presentation in the annual Journal of the American College of Allergy, Asthma and Immunology Scientific Meeting.
Ruchi S. Gupta
“Prevalence rates of food allergies vary widely in previous studies due to geographic, socioeconomic, dietary, and health care access factors, as well as differences in study design and assessment tools,” Gupta told Healio. “In most cases, prevalence rates of food allergy are reported for certain age groups or specific allergens. The aim of ASSESS FA was to provide comparable assessments across countries, age groups and food allergens using a standardized and consistent methodology.
From October 2022 to February 2023, Gupta and colleagues conducted an interim, international, population-based study of self-reported data in four age groups: adults (aged 18-65), adolescents (aged 12-17 years) and parents/guardians of toddlers (ages 6 months-5 years) and older children (ages 6-11 years). Overall, 42,250 children and 40,537 adults from the US, Canada, UK, France, Germany, Italy, Spain and Japan participated in the study.
The study included a 30-minute questionnaire of self-reported data related to a physician’s diagnosis of food allergy, symptoms of an allergic reaction, and time between allergen exposure and onset of symptoms. The researchers specifically looked at six common allergens: peanuts, milk and/or milk products, shrimp, shellfish, tree nuts and eggs.
Researchers define a symptom-conclusive food allergy as an allergic reaction that includes a list of predetermined symptoms — including hives on the body, mouth, or throat; lip/tongue or other swelling; tightness in the throat or chest; Lack of air; difficulty breathing; wheezing; vomiting; and fainting, lightheadedness, or dizziness—and that occur within 120 minutes of food exposure.
“It can be very complicated when you’re self-reporting [food allergy] because these symptoms [could] just to be something like stomach pain, cramping, so that wasn’t included,” Gupta said during his presentation.
Overall, the results showed that the point prevalence of convincing food allergy varied among children from 2.4% (95% CI, 1.9%-2.8%) in Germany to 7.5% (95% CI, 6, 7%-8.2%) in Canada and among adults from 2.1% (95% CI, 1.7%-2.5%) in Japan to 6.5% (95% CI, 5.8%- 7.4%) in Italy.
When considering the three groups of children, Canada showed the highest and Germany the lowest prevalence rates for children aged 6 months to 5 years (6.9%; 1.8%) and 6 to 11 years (6.7%; 2.7%). In children aged 12 to 17 years, Canada again showed the highest prevalence rates, while Japan showed the lowest (8.7%; 2.6%).
Differences also emerged when looking at specific allergens. For example, the point prevalence of peanut allergy was 2% (95% CI, 1.6%-2.3%) among children and 1.6% (95% CI, 1.1%-2.1%) among adults in USA, as well as 3.9% (95% CI, 3.4%-4.5%) among children and 1.4% (95% CI, 1%-1.8%) among adults in Canada, compared with 0.7% (95% CI, 0.5%-0.9%) among children and 0.3% (95% CI, 0.2%-0.4%) among adults in Japan.
Gupta also noted that these data indicate a 1.3% (95% CI, 0.9%-1.7%) prevalence of shellfish allergy among US adults, which is lower than the 3% incidence commonly reported in literature.
“So there is a little variability, but the data still shows the highest [prevalence of shellfish allergy] in the U.S.,” Gupta said, adding that using a symptom-convincing food allergy avoids overestimating and underestimating the prevalence of food allergy.
“We always have this discussion about, if you’re just going by symptoms and patient reports, are we overestimating?” she said. “But we’ve found in the U.S. and around the world that many children and adults are not receiving a formal diagnosis. They don’t make it to an allergist. So which is the best way? There is an underestimation if you go by the doctor’s diagnosis alone, or perhaps an overestimation if you go only by the parents’ reports. So the happy medium is compelling symptoms that agree.”
Overall, these results aren’t that surprising, Gupta said.
“The FA prevalence rates found in ASSESS FA are similar to those reported in the literature, with the exception of China,” she told Healio, adding that one region in particular in China showed higher rates that the researchers currently investigating.
Since the researchers now have this tool that can be used to determine the prevalence of food allergy, they plan to look at more countries.
“We will present additional results, including the risk stratification framework, which defines different food allergy risk profiles based on the clinical severity of food allergy, the prevalence of food allergy in adulthood, and the burden of food allergy on the patient’s quality of life. ” she said.
Gupta RS, et al. Summary A033. Presented at: ACAAI Annual Scientific Meeting; November 9-13, 2023; Anaheim, California.
Disclosures: Gupta reports serving as a consultant/advisor for and/or receiving research support from Aimmune, Food Allergy Research & Education, Genentech, NIH, and Novartis and has an ownership interest in Yobee Care Inc.