Supplementary Material for: Prevalence of Hidradenitis Suppurativa in Lyon: results from the French team of the Global Hidradenitis Suppurativa Atlas project

Introduction: The exact prevalence of hidradenitis suppurativa (HS) remains elusive, in France as elsewhere. The GHiSA (Global Hidradenitis Suppurativa Atlas) project is a unique opportunity not only to determine the exact prevalence in each participating centre, but also to help estimate the global prevalence and provide a basis for comparing centres with each other and obtaining potential pathophysiological indications.

Methods: A French version of the questionnaire developed for the GHiSA initiative was proposed to healthy adults accompanying a patient to the outpatient clinic.

Results: The prevalence of HS in the 525 participants was 3.4% (95% confidence interval: 2.2% – 5.4%). The HS patients were 10 females and 8 males, were significantly younger than non-HS controls and more frequently smokers. The screening questionnaire showed a 100% sensitivity and negative predictive value.

Discussion: The estimated prevalence here is more than three times higher than the 1% prevalence usually recognised in Western countries. It remains to be determined whether this increase is apparent (freedom of speech; methodological differences compared with previous studies, which contribute to the usual figure of 1%) or real. In the latter case (gross increase in the prevalence of the disease), the underlying mechanisms need to be explored, and comparison with the results observed in other GHiSA centers will be decisive.

引言：化脓性汗腺炎（HS）的确切患病率在法国乃至世界各地均难以确切查明。全球化脓性汗腺炎图谱（GHiSA）项目不仅为各参与中心确定确切患病率提供了独特的机遇，而且有助于估计全球患病率，并为比较各中心及获取潜在的病理生理学指征奠定基础。
方法：针对GHiSA倡议开发的问卷的法国语版本被提出用于陪同患者前往门诊诊所的健康成人。
结果：在525名参与者中，HS的患病率为3.4%（95%置信区间：2.2% – 5.4%）。HS患者中，女性10例，男性8例，与无HS对照组相比显著年轻，且吸烟者更为常见。筛查问卷显示100%的敏感性和阴性预测值。
讨论：此处估计的患病率是西方国家通常认为的1%患病率的超过三倍。尚需确定这一增加是显著性的（言论自由；与先前研究的方法学差异，这有助于维持1%的常规数字）还是真实的。在后一种情况下（疾病患病率的显著增加），需要探究其潜在机制，并与其他GHiSA中心的观察结果进行比较将至关重要。