Supplementary Material for: Ethnic Differences in Hidradenitis Suppurativa: Comorbidities, Lesion Distribution, and Disease Severity in a Taiwanese Population

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory debilitating disorder showing ethnic heterogeneity in its clinical presentation and associated comorbidities. However, data on East Asian populations remain scarce. Methods: We conducted a retrospective analysis of clinical records for patients with HS diagnosed between 2006 and 2022 at two tertiary referral hospitals in Taiwan. Age- and sex- matched reference individuals without HS (3:1 ratio) were randomly selected from dermatology outpatients. Association between comorbidities and HS were analyzed using conditional logistic regression, while logistic regression identified predictors for lesion distribution and disease severity. Results: A total of 512 patients with HS and 1,536 reference individuals were identified. Comorbidities independently associated with HS were obesity, smoking, and diabetes. Men had 4.2 times the odds of developing gluteal lesions but only 0.5 times the odds of axillary or inguinal involvement compared to women. Current smokers had 2.8 times the odds of gluteal involvement but 0.6 times the odds of having axillary lesions. A significant association was observed between obesity and axillary involvement. Advanced disease (Hurley stage II and III) was significantly associated with male sex, smoking, and axillary involvement. Conclusion: Our study highlights distinct lesion distribution in East Asian patients with HS. Male sex and active smoking could predict for gluteal involvement, while female sex and obesity for axillary involvement. Independent risk factors for advanced disease were male sex, smoking, and axillary involvement.

背景：化脓性汗腺炎（Hidradenitis Suppurativa，HS）是一种慢性炎症性致残性疾病，其临床表现与合并症存在种族异质性，但目前针对东亚人群的相关研究数据仍较为匮乏。方法：本研究对2006年至2022年间中国台湾两家三级转诊医院确诊的HS患者的临床病历开展回顾性分析；按年龄与性别匹配的非HS对照个体（对照与病例比例为3:1）从皮肤科门诊患者中随机选取。采用条件logistic回归分析合并症与HS的关联，通过logistic回归明确皮损分布及疾病严重程度的预测因素。结果：最终共纳入512例HS患者及1536例对照个体。与HS独立相关的合并症包括肥胖、吸烟及糖尿病。相较于女性，男性发生臀部皮损的优势比为4.2，而发生腋窝或腹股沟受累的优势比仅为0.5；当前吸烟者发生臀部受累的优势比为2.8，但发生腋窝皮损的优势比为0.6。肥胖与腋窝受累存在显著关联。疾病晚期（Hurley Ⅱ期及Ⅲ期）与男性性别、吸烟及腋窝受累显著相关。结论：本研究揭示了东亚HS患者独特的皮损分布特征。男性性别及主动吸烟可预测臀部受累，而女性性别及肥胖可预测腋窝受累；疾病进展的独立危险因素包括男性性别、吸烟及腋窝受累。