Gender, racial, ethnic, and Fitzpatrick skin type representation in Acanthosis nigricans clinical trials

Acanthosis nigricans (AN) is characterized by dark, velvety patches and thin plaques primarily in the body folds. AN is more prevalent in skin of color populations, including Black/African American, Native American, and Hispanic patients. As the U.S. population becomes increasingly diverse, the need for inclusive dermatologic research becomes more pressing. Given the increased prevalence of AN in skin of color patients, there is a need to evaluate representation in AN clinical trials. This study aims to uncover gender, race, ethnicity, and Fitzpatrick skin type (FST) representation in AN clinical trials. A systematic literature search was performed across PubMed, Embase, and Cochrane databases to identify participant characteristics in clinical trials focused on AN treatment. Our review yielded 21 clinical trials, totaling 575 participants, with an identified predominance of female participants (69.0%) and a surprising absence of race or ethnicity data. Out of the 11 studies that included FST data, 1.2% of participants were type II, 20.6% were type III, 50.0% were type IV, and 28.2% were type V. None of the participants were FST I or VI. Herein, we highlight a predominate inclusion of female and FST III-V patients in AN clinical trials, the populations most impacted by this condition. We also highlight the need for improved race and ethnicity reporting and the importance of including all FSTs in clinical studies. Addressing this gap is critical for developing safe, efficacious, patient-centered, and equitable treatments for all AN patients. Future research should prioritize comprehensive inclusion of race, ethnicity, and the full spectrum of FSTs.