A new study found that individuals living in lower-income neighborhoods may have a higher risk of being diagnosed with hidradenitis suppurativa, a chronic inflammatory skin condition.
Investigators analyzed data from 65,766 dermatology patients in the San Francisco Bay Area who received care between August 2019 and May 2024. Among them, 485 patients were newly diagnosed with hidradenitis suppurativa (HS).
HS causes painful lumps and scarring, most often in the underarms, groin, and similar areas. While smoking and obesity are known risk factors, the investigators explored the role of neighborhood-level influences.
Neighborhoods were grouped into five levels based on socioeconomic status (SES), with quintile 1 (Q1) representing the lowest and quintile 5 (Q5) the highest. After adjusting for age, sex, and race and ethnicity, patients in Q1 neighborhoods had 3.32 times the risk of receiving a new HS diagnosis compared with those in Q5.
The risk decreased with increasing SES. The odds ratios were 2.25 in Q2, 1.97 in Q3, and 1.44 in Q4 compared with Q5, demonstrating a significant trend across SES levels.
Patients diagnosed with HS were younger on average (35.6 vs 50.5 years) and more likely to be female (72.8% vs 57.9%), Black (19.2% vs 3.7%), or Hispanic (17.3% vs 7.4%) compared with those without HS.
The investigators also examined whether obesity and smoking mediated the link between SES and HS. In the subset of patients with body mass index data, obesity explained 35% of the increased risk in Q1 neighborhoods. Smoking showed a weaker, statistically nonsignificant effect.
Stratified analyses showed that the increased HS risk in low-SES neighborhoods was observed across racial and ethnic groups, although the strength and statistical significance varied. Among Hispanic patients, those in Q1 neighborhoods had 7.62 times the risk of HS diagnosis compared with those in Q5.
The investigators used diagnosis codes confirmed through chart reviews from a single academic health system. While its design didn't prove causality, the consistent SES trend suggested that neighborhood conditions may influence HS risk.
The investigators noted that environmental and structural factors—such as access to health care, food availability, physical activity, and exposure to stress or pollutants—may contribute to HS risk and interact with individual-level factors like obesity.
Although the study focused on the San Francisco Bay Area, the findings may have broader implications for other urban regions with similar socioeconomic disparities.
Full disclosures are available in the study.
Source: JAMA Dermatology
