Hidradenitis suppurativa in Black and White patients - a clinical study.

OBJECTIVE: It is suggested that hidradenitis suppurativa (HS) is more prevalent and causes greater morbidity in Black patients than in White. Clinical data are however lacking.

PATIENTS AND METHODS: We therefore describe HS risk factors, disease severity and clinical phenotypes in the Blacks and Whites. Patients referred for HS between 1984 and 2019 at the Johns Hopkins Hospital were identified using the Pathology Data System (PDS). Clinical and sociodemographic characteristics were extracted and the van der Zee & Jemec HS clinical phenotypes were recovered.

RESULTS: A total of 278 patients were identified. Ethnically, 108 (38.8%) were White, and 170 (61.2%) Black. The following HS phenotypes were found: Regular (n=193, 69.4%), scarring folliculitis (n=40, 1.4%) frictional furuncle (11.2%), conglobata (n=9, 3.2%), syndromic (n=3, 1.1%) and ectopic (n=2, 0.7%). No statistically significant ethnic differences in clinical presentation were found. Blacks however had more severe diseases than Whites (p= 0.024 for trend). With multivariate logistic regression analysis, we found that male sex, disease duration, and smoking were independent predictors of regular HS phenotype. Major limitations are the limited number of cases studied and the lack of data regarding response to therapies.

CONCLUSIONS: Demographics and phenotypical presentation of HS patients do not seem to be associated with Black ethnicity. However, there is a significant trend for Blacks to present with more Hurley stage 2 and 3 disease compared to White patients. It is speculated that ethnic differences are epiphenomena to social factors, highlighting the broader importance of ethnicity.