Neighborhood Socioeconomic Status and New Hidradenitis Suppurativa Diagnoses in a Single Health System.

Importance: Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition. Risk factors for developing HS (eg smoking and obesity) are influenced by social drivers of health at the neighborhood level. However, the association of neighborhood-level socioeconomic status (nSES) and HS has not been adequately assessed.

Objective: To evaluate the association of nSES with new HS diagnoses among dermatology patients within a single health system.

Design, setting, and participants: This was a cross-sectional study of patients of the dermatology clinics at the University of California San Francisco health system between August 1, 2019, and May 31, 2024, who were also residents of the San Francisco Bay Area at index visit. Data analyses were performed from June 1, 2024, to February 11, 2025.

Exposure: Census tract-level index measure of nSES that incorporated income, poverty, housing cost, rental cost, education, occupation, and employment. Quintiles of nSES were assigned based on nSES distribution in the San Francisco Bay Area counties.

Main outcomes and measures: A new HS diagnosis during the study period, identified by the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code, and confirmed by medical record review. Logistic regression models were constructed and fit by generalized estimating equations accounting for clustering by census tract with nSES quintile as the primary exposure (reference used was quintile 5, the highest nSES quintile); new HS diagnosis as the binary outcome; and age, sex, and race and ethnicity as confounders. In secondary analyses, smoking status, obesity, and health insurance type were assessed as possible mediators.

Results: The analyses included a total of 65 766 patients (mean [SD] age, 50.4 [18.3] years; 41.8% female), of whom 485 (0.7%) had a new HS diagnosis. Greater odds of a new HS diagnosis were observed in lower-SES neighborhoods (Q1-Q4)-after adjusting for age, sex, and race and ethnicity, odds ratio for Q1 was 3.32 (95% CI, 2.46-4.49); Q2, 2.25 (95% CI, 1.62-3.12); Q3, 1.97 (95% CI, 1.46-2.66); and Q4, 1.44 (95% CI, 1.06-1.96) (P <.001 [linear trend]). In race-stratified analyses, greater odds of a new HS diagnosis were observed among patients residing in lower-SES neighborhoods, although this pattern did not reach statistical significance at the 5% level in all racial and ethnic groups.

Conclusions and relevance: This cross-sectional study found that nSES was independently associated with a new diagnosis of HS among dermatology patients. This finding supports the hypothesis that neighborhood-level factors may influence the development of HS.