Erythema scores for cutaneous lupus trial eligibility limit skin of color representation

Key takeaways:

• White patients experienced red erythema more frequently than Black patients (mean erythema score, 1.58 vs. 1.36; P < .001).
• Black patients exhibited pink erythema more than white patients (42% vs. 24%).

Requiring erythema alone for entry into cutaneous lupus erythematosus trials may exclude patients with skin of color and increase health disparities, according to a study.

“Measures that use erythema as the primary determinant for disease severity may be less dependable for patients with skin of color,” Lillian Xie, BS, a medical student in the department of dermatology at the Perelman School of Medicine at the University of Pennsylvania, and colleagues wrote. “Our study investigates erythema variability across [cutaneous lupus erythematosus (CLE)] subtypes and racial groups to determine whether trial representation mirrors demographic characteristics and subgroup prevalence of the overall population with CLE.”

The cross-sectional study included 377 adults with CLE (mean age, 45.2 years; 80.9% women), 60.5% of which were white, 30.5% Black and 9% Asian, multiple races, Native American/Pacific Islander or unknown. Also, 2.9% were Hispanic/Latino. Among these patients, 64.5% had chronic CLE, 27.3% had subacute CLE and 8.2% had acute CLE.

The Cutaneous Lupus Erythematosus Disease Area and Severity Index - Activity divided by affected areas was used to determine mean erythema scores. These scores were considered pink when between 1 to 1.49 and red when 1.5 or greater based on the Cutaneous Lupus Activity IGA.

Results showed that there were significant differences in average erythema across subtypes. The only subtypes routinely classified as having red erythema were subacute CLE at a mean score of 1.62 (P < .001) and hypertrophic chronic CLE at mean score of 1.78 (P = .006).

White patients experienced red erythema more frequently than Black patients (mean erythema score, 1.58 vs. 1.36; P < .001). Asian patients and those of other races were also less likely to exhibit red erythema (mean erythema score, 1.3; P = .002).

In fact, the perception of pink erythema among those that would typically meet entry criteria for a CLE clinical trial due to having a score of 8 or higher on the CLE Disease Area and Severity Index was much higher in Black vs. white patients (42% vs. 24%). This implied that these Black patients would have been excluded from trials where red lesions were a requirement for entry, according to the study.

“Based on the erythema distribution shown through our data, requiring a minimum average of lesions scored as red to qualify as moderate to severe disease would limit the enrollment of patients with darker skin tones,” the authors wrote. “In fact, such a requirement would disproportionately exclude already underrepresented populations.”

The authors concluded that requiring this criterion for entry into CLE clinical trials would contribute to research bias and increase health disparities. To ensure equality of care, the investigators urged fellow researchers to conduct their trials so that the demographic and disease subtype of the target population is represented fairly.