Race may play an important role in children's food allergies

Black children have significantly higher rates of shellfish and fish allergies than White children, in addition to having higher odds of wheat allergy, suggesting that , researchers at Ann & Robert H. Lurie Children's Hospital of Chicago, Rush University Medical Center and two other hospitals have found.

Results of the study were published in the February issue of the Journal of Allergy and Clinical Immunology: In Practice.

Food allergy is a common condition in the U.S., and we know from our previous research that there are important differences between Black and White children with food allergy, but there is so much we need to know to be able to help our patients from minority groups. In this current paper, our goal was to understand whether children from different races are allergic to similar foods, or if there is a difference based on their racial background."

Mahboobeh Mahdavinia, MD, PhD, Study's First Author and Chief, Division of Allergy and Immunology, Rush University Medical Center

Findings are a part of a large, multicenter national trial, called Food Allergy Management and Outcomes Related to White and African American Racial Differences (FORWARD), which aims to explore potential racial differences and disparities in food allergy outcomes including healthcare utilization, allergic reaction manifestation, management practices, and psycho-social outcomes.

"Previous studies indicate that cockroach exposure may be an important mechanism by which children develop a shellfish allergy. The immune system can confuse certain proteins in seafood with similar proteins that are present in the muscles of cockroaches that commonly elicit an allergic response," said Mahdavinia. "For example, research has suggested that shellfish allergy may occur from inhaling tropomyosin, the protein of two common household allergens, dust mite and cockroach, which share 80% of amino acid sequencing with shellfish. Tropomyosin, which regulates muscle contraction and relaxation, also has been found in fin fish."

Food allergy is a major public health concern, affecting 8% of children in the United States, with an estimated economic burden of $24.8 billion annually. For people with food allergies, eating a tiny amount of food can trigger symptoms such as hives, breathing, digestive problems, and/or anaphylaxis (a severe, potentially fatal allergic reaction).

"National surveys have shown that the prevalence of food allergy in general has been increasing in children in the U.S. among all races/ethnicities. However, much remains unknown about why certain allergies are more likely to affect children of particular races and ethnicities and how those racial/ethnic minority patients are affected," said the lead principal investigator of the study and senior author Ruchi Gupta, MD, MPH, Director of the Center for Food Allergy and Asthma Research at Northwestern University Feinberg School of Medicine and a physician at Ann & Robert H. Lurie Children's Hospital of Chicago.

Gupta, Mahdavinia, and colleagues are conducting a large study of children ranging in age from birth to 12 years old who are diagnosed with food allergy and were seen in allergy/immunology clinics at four urban tertiary care centers in the U.S., which include Rush University Medical Center, Ann & Robert H. Lurie Children's Hospital of Chicago, Cincinnati Children's Hospital Medical Center, and Washington D.C.'s Children's National Hospital. The study included 664 children and was composed of 36 percent non-Hispanic Black and 64 percent non-Hispanic White children.

While scientists are still trying to figure out the exact mechanism of the allergy, the findings provide further insight into the importance of reducing Black children's exposure to cockroaches.

"This information can help us care for not only a child's food allergy, but all of their allergic diseases, including asthma, allergic rhinitis, and atopic dermatitis," said Susan Fox, PA-C, MMS, who is a co-author of the study and an allergy and immunology physician assistant at Rush University Medical Center.

In this study, the Black children with food allergies were more likely to have asthma. The study also showed that children with a shellfish allergy were more likely to have more severe asthma, while other food allergens were not associated with a diagnosis of asthma.

"A major concern is that there is a higher prevalence of asthma in Black children with food allergies when compared with White children with food allergies. Approximately 70% of fatal food anaphylaxis is accompanied by asthma. Black children are at a two- to threefold risk of fatal anaphylaxis compared to White children," Mahdavinia said. "By knowing this information, it can identify patients most at risk.

"We need to conduct further research to identify food allergies and food sensitivities among all races and ethnicities so we can develop culturally-sensitive and effective educational programs to improve food allergy outcomes for all children," Mahdavinia added.