Racial differences in food allergy diagnostics: Utilization and outcomes at a single center

In the United States, food allergy (FA) is more prevalent among Black children and adults than among White populations. The reason for this observed difference is unknown.

To propose that bias in FA testing contributes to this difference and hypothesize that Black patients face higher rates of false-positive FA testing compared with White patients.

Retrospective data were extracted from 6251 patients who were evaluated for FA at a single center. Analyses compared diagnostic utilization rates, oral food challenge (OFC) outcomes, and specific IgE (sIgE) and skin prick test results among patients of different races.

Black patients had higher levels of sIgE on average compared with White patients for tree nuts (12.0 [95% CI = 9.8-14.6] ng/mL vs 8.4 [95% CI = 6.9-10.1] ng/mL; P < .001) and all food allergens combined (14.8 [95% CI = 13.7-15.9] ng/mL vs 13.8 [95% CI = 12.8-14.8] ng/mL; P < .001). No significant differences were found for skin prick test wheal or flare diameters. In addition, a significantly lower percentage of Black patients evaluated in the clinic underwent an OFC compared with White patients (2.2% vs 4.8%; P < .001) despite higher rates of tolerating an OFC (90.6% vs 85.7%; P = .02).

Higher sIgE levels in Black patients may lead physicians to order OFCs less frequently, potentially contributing to overdiagnosis and the observed racial difference in FA prevalence. Further investigation is warranted to determine whether the threshold for ordering OFCs should be adjusted to account for potential differences in clinical markers, such as sIgE levels, across racial and ethnic groups.