People with discoid lupus erythematosus (DLE) living in areas marked by poverty tended to have more severe manifestations, a study in Philadelphia found, whereas associations with racial identity were relatively weak.
Odds of showing moderate to severe skin damage, as quantified with the Cutaneous Lupus Erythematosus Disease Area and Severity Index damage score (CLASI-D ≥6), were roughly quadrupled among residents of census blocks with an "area deprivation index" (ADI) score greater than 5, compared with blocks rated at 5 or less (OR 3.90, 95% CI 1.27-12.69), according to Katharina S. Shaw, MD, of the University of Pennsylvania in Philadelphia, and colleagues.
Similarly, odds of showing high CLASI scores for disease activity (CLASI-A ≥10) were also strongly associated with ADI values greater than 5 (OR 3.31, 95% CI 1.27-9.44), the researchers .
Consistent with prior research, damage severity rates differed significantly by race, with 87% of Black patients being characterized as having moderate-to-severe disease compared with 52% of white patients (P<0.001), but after adjusting for ADI and other confounders, race was not significantly associated with higher CLASI-D severity (OR 2.78, 95% CI 0.95-8.44).
"The findings of this cross-sectional study suggest that socioeconomic and behavioral factors are pivotally associated with DLE disease severity. These results may prompt a reevaluation of the role of race in DLE disease severity," Shaw and colleagues wrote.
"While racial disparities existed within the study population, their association with disease severity may be partially explained by area disadvantage, which is a measure of structural inequity," they continued. "This emphasizes the importance of adopting a more nuanced, root-causal perspective that considers the socioeconomic context within which racial disparities are observed."
As the authors observed, DLE "is the most common form of chronic cutaneous lupus erythematosus and is characterized by its ability to cause irreversible scarring, dyspigmentation, and disfigurement." Prevalence is higher in Black people versus whites, and also tends to show more severe manifestations. But because Black Americans also tend to be poorer, it hasn't been clear how much these disparities stem from genetics or socioeconomic deprivation.
Rather than examine household income or educational attainment, however, Shaw's group chose to focus on neighborhood factors as "one aspect of the ." They relied on the to put numbers to this complex parameter. It combines 17 pieces of neighborhood-level data, covering education, employment, housing quality, and wealth indicators, into a single index value. Earlier applications had set a range of 40-160, with 100 meant to reflect an average level of deprivation. But Shaw and colleagues used a range of 1-10 for the current study, with higher values indicating greater socioeconomic disadvantage.
The investigators identified 154 adult DLE patients seen at the University of Pennsylvania's rheumatology-dermatology specialty clinic from 2007 to 2024. Some 64% were Black and 30% were white. At their first clinic visit, about one-quarter had moderate-to-severe disease activity and three-quarters had moderate-to-severe damage; CLASI scores at these initial encounters were the basis for the study's statistical analyses. Just over one-third also had systemic lupus erythematosus (SLE). ADI scores were based on patients' home addresses.
Half the cohort lived in neighborhoods with ADI ratings greater than 5. As expected in a major U.S. urban center, Black patients were far more likely to live in deprived neighborhoods -- the mean rating for Black patients was 6.8, versus 2.7 for white patients.
When examining other factors associated with more severe disease activity and damage, smoking status and SLE diagnosis stood out. After adjusting for other parameters, odds ratios for moderate-severe damage were 3.15 for current smoking and 3.63 for SLE; for moderate-to-severe disease activity, odds ratios were 2.20 and 1.97, respectively (the latter fell short of statistical significance).
"[S]moking cessation programs should be made accessible to all patients with DLE, with a particular emphasis placed on more disadvantaged areas," Shaw and colleagues wrote. "Incorporating these programs into routine care could mitigate a key modifiable risk factor for DLE exacerbation."
And the researchers argued that neighborhood deprivation is at least potentially modifiable as well. "[C]linical trials and policy makers should consider geographically targeted strategies that address the multifaceted barriers faced by residents in these areas. Such strategies might include increasing transportation, improving access to healthcare facilities, partnering with patients in the community to foster medical trust, enhancing patient education, and improving affordability and accessibility of medications," the group suggested.
The study's cross-sectional design was an important limitation cited by the authors. So was the reliance on records from patients' initial clinic visits, which "may not adequately reflect the influence of ongoing treatment regimens on disease severity, as treatment details, such as type, duration, and adherence, were not available." Other limitations included the focus on inner-city Philadelphia, such that the findings may not generalize to other settings.
"Future studies with larger sample sizes are necessary to further elucidate the association between the 17 components of the ADI with DLE disease severity," Shaw's group concluded.
Disclosures
The study was funded by U.S. government grants and Lupus Therapeutics.
Shaw had no disclosures. Co-authors reported relationships with numerous pharmaceutical companies and other commercial entities.
Primary Source
JAMA Dermatology
Faden DF, et al "Area deprivation and disease severity in adult patients with discoid lupus erythematosus" JAMA Dermatol 2024; DOI: 10.1001/jamadermatol.2024.2355.