Racial differences have been observed in the prevalence and presentation of atopic dermatitis in African American and European American patients. African Americans tend to present with extensive papular lesions and widespread extensor surface involvement, as well as lichenification secondary to treatment resistance.
Few studies have been conducted on the immune signatures that may drive disease, especially in African Americans who are disproportionately affected. Broad immune activation may be involved, especially at the Th2 and Th17 axes. This cross-sectional study, performed at Johns Hopkins University and published in Scientific Reports, sought to examine, at a molecular level, moderate to severe pruritus associated with atopic dermatitis in African Americans.
A total of 18 skin biopsies were conducted, including lesional, non-lesional, and control biopsies. Adults with self-reported moderate or severe itching were included, and healthy controls were assigned to match the patients with atopic dermatitis by age, sex, and race.
Ultimately, Th2 and Th22 cutaneous signatures, as well as novel Th1 and Th17 cutaneous signatures, were found to be upregulated in African Americans with atopic dermatitis compared to healthy controls. Systemic inflammatory markers, such as ESR, CRP, ferritin, and blood eosinophils, were also found to be higher in African Americans with atopic dermatitis than in white Americans with atopic dermatitis.
In closing, healthcare providers should seek to understand more clearly the immune pathways that can influence the development and presentation of atopic dermatitis. Severe disease in African Americans with atopic dermatitis may call for systemic immune therapies that target key pathways, especially those that involve Th17 upregulation [1].
Source:
[1] Wongvibulsin, S., Sutaria, N., Kannan, S., Alphonse, M. P., Belzberg, M., Williams, K. A., Brown, I. D., Choi, J., Roh, Y. S., Pritchard, T., Khanna, R., Eseonu, A. C., Jedrych, J., Dillen, C., Kwatra, M. M., Chien, A. L., Archer, N., Garza, L. A., Dong, X., . . . Kwatra, S. G. (2021). Transcriptomic analysis of atopic dermatitis in African Americans is characterized by Th2/Th17-centered cutaneous immune activation. Scientific Reports, 11(1). https://doi.org/10.1038/s41598-021-90105-w
