Distinct Allergic Trajectories Observed in Black and White Children with AD

Investigators noted that the study of the atopic march has largely focused on White populations that biased current paradigms

An investigation presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting (AAAAI) 2022 on atopic dermatitis found that Black and White children had distinct allergic trajectories that were defined by different longitudinal endotypes.

Black children exhibited higher asthma risk despite a more intact skin barrier, and less sensitization to food allergy and allergic rhinitis. White children had less asthma risk despite a more dysfunctional skin barrier and more food allergy and allergic rhinitis sensitization.

Investigators noted that the study of the atopic march had largely been limited to White populations that biased current paradigms.

As such, a team of investigators led by Jocelyn Biagini, PhD, Cincinnati Children’s Hospital Medical Center, defined the atopic march in Black and White children and explored mechanisms of racial differences.

The Methods

The team utilized the cohort Mechanisms of Progression of Atopic Dermatitis to Asthma in Children (MPAACH) study to assess longitudinal sensitization. These 601 participants were also assessed based on SCORAD, transepidermal water loss (TEWL), skin filaggrin (FLG) expression, exposures and genetic heritability.

The Findings

Biagini and colleagues observed that White children from the cohort were more likely to be sensitized to aero/food allergens (p=0.0001) and over 3-tomes more likely to be sensitized to food allergy and allergic rhinitis without asthma risk (p<0.0001).

Contrastingly, Black children were over 6 times more likely to have high asthma risk without food allergy, sensitization, or allergic rhinitis (p<0.0001).

White children had decreased non-lesional keratinocyte FLG expression (p=0.02) but higher lesional and non-lesional TEWL, while Black children had increased genetic heritability for asthma risk and higher exposures to secondhand smoke and traffic-related air pollution.

“The observed racial differences are likely due, in part, to increased genetic heritability for asthma risk and harmful environmental exposures in Black children,” the team wrote. “Our findings provide a new atopic march paradigm that is inclusive of Black children.”