Black children were more likely to have wheat, soy, and seafood allergies than white children, with the starkest differences seen with shellfish, survey data from the FORWARD cohort showed.

The analysis of phenotypic differences among a sampling of close to 650 food-allergic children showed that nearly one in four Black children under age 5 had shellfish allergies (24.1%), compared with just 3.6% of white children. In kids 5 years and up, these rates were 39.2% and 14.0%, respectively (P<0.001 for both), according to Christopher Warren, PhD, of Northwestern University Center for Food Allergy and Asthma Research in Chicago.

Black children in the younger cohort had elevated rates of allergies to fin fish compared with white children as well (13.9% vs 5.4%), and significantly higher rates of fin fish allergies were seen among older Black kids (30.1% vs 12.3%, P<0.001).

“Food allergy affects over 32 million Americans, including roughly 8% of U.S. kids, many of whom experience severe reactions which result in substantial healthcare utilization and economic burden,” Warren said during his video presentation at the virtual American College of Allergy, Asthma & Immunology annual meeting.

In kids under 5, wheat allergies were numerically higher in Black versus white children (11.4% vs 5.4%), and significantly elevated in the older group of Black children, with rates of 14.4% and 3.9%, respectively (P<0.01).

Similarly, soy allergies in Black children were numerically higher in the younger group (8.9% vs 6.3% of white kids), and significantly higher in those age 5 and above (12.4% vs 5%, P<0.05).

In the younger group, 38% of Black children had allergies to multiple “top 9” allergies, versus 35.4% of white children. For the older group, these rates were 71.2% versus 62%, respectively.

“Although obviously further work is needed to ensure [these findings] are externally valid and representative of the broader Black and white population, these data support other population level data collected by our group and others indicating that Black children are more likely to be multi-food allergic and have particularly high rates of seafood allergy relative to their white peers,” Warren said.

Warren said growing evidence suggests that food allergies can be more severe among Black children.

A recent survey conducted by Warren and colleagues found Black children to be twice as likely as white children to have allergies to multiple foods (OR 2.0, 95% CI 1.3-2.8), though he cautioned that there are significant limitations to the inferences that can be drawn from cross-sectional parent-report surveys.

To address this limitation, the researchers established a multisite, longitudinal cohort of Black and white families with food allergic children in an effort to better characterize phenotypic and endotypic differences in food allergies by race.

The FORWARD study cohort was designed to include 1,000 families from four pediatric academic medical centers — in Chicago, Washington, and Cincinnati — with enrollment planned for completion in December of 2020. The current analysis included 239 Black children and 409 white children. (Warren said the group recently received funding to include Hispanic families in the study as well.)

Roughly half (47%) of the sample had physician-diagnosed seasonal allergies, including 61.7% of Black children and 38.6% of white children, and 38% of the entire sample had current asthma. Black children were roughly twice as likely to have environmental or seasonal allergies (61.7% vs 38.6%) and current asthma (57.8% vs 27.1%) compared with whites.

In race-stratified estimates of the most prevalent food allergies, no significant differences were shown in overall peanut, egg, and milk allergy prevalence by race in both younger and older children.

For specific shellfish, the younger group of Black kids had higher rates of allergy to shrimp (20.3% vs 2.7%), lobster (11.4% vs 1.8%), crab (13.9% vs 2.2%), oyster (10.1% vs 1.3%), scallop (10.1% vs 1.8%), and crayfish (10.1% vs 1.8%; P<0.01 for all).

Differences were even more pronounced among the older group of Black children, who compared to white children had higher rates of allergies to shrimp (36.6% vs 12.3%), lobster (32.7% vs 10.1%), crab (31.4% vs 10.1%), mussel (26.1% vs 6.1%), oyster (26.1% vs 6.7%), scallop (30.1% vs 6.1%), and crayfish (28.1% vs 5.6%; P<0.001 for all).

This was consistent with previous work showing a higher preponderance of shellfish allergies among Black children and adults, Warren said.

For specific fin fish allergies, Black children age 5 and older reported significantly higher rates of allergic reactions to salmon (22.2% vs 8.4%), grouper (18.3% vs 3.9%), swordfish (18.3% vs 4.5%), catfish (22.9% vs 3.9%), tuna (21.6% vs 7.3%), cod (23.5% vs 8.4%), halibut (19.0% vs 6.1%), and tilapia (24.8% vs 8.4%; P<0.001 for all).

Warren concluded that the findings highlight the need for greater emphasis on seafood allergy research, treatment, and prevention approaches, which have not been studied as much as peanut, wheat, and other food allergies.