Early Pathophysiology of Hidradenitis Suppurativa and Prediction of the Risk of Progression: a Prospective Cohort

Hidradenitis suppurativa (HS) is a chronic inflammatory disease affecting approximately 1% of the population. Most pathophysiological studies have focused on advanced forms (Hurley II-III), which obscures the initial mechanisms. The mean diagnostic delay of 7 to 10 years and the lack of prognostic biomarkers limit early management. Identifying molecular and microbiological alterations as early as Hurley stage I could allow stratification of the risk of progression and support early intervention strategies.

Inclusion Criteria: HS patients: * Age ≥ 12 years * Consultation for a recurrent abscess or nodule in an HS area (axillary, inframammary, abdominal, inguinal, perineal, intergluteal and intermammary regions) * At least one inflammatory lesional area accessible to biopsy outside skin folds and the face. A fold is defined as the area within 1 cm of the crease. * First episode within the past 12 months * Free, informed, written and signed consent (adult patient, or holders of parental authority + assent of the minor) * Affiliation to a social security scheme Controls: * Healthy control enrolled in the ImmuneSkinBank research protocol coordinated by the same investigating team (IDRC 2024-A00202-45, APHP240183, favourable opinion from CPP Sud-Méditerranée II), who agreed to the reuse of their data and samples for future research. * Matched to an HS patient on age (by age group) and sex * Informed about the study by an information notice sent by post Exclusion Criteria: HS patients: * Buttock involvement * HS-related sinus tracts (Hurley II or III) * Treatment that may interfere with the course of HS: * Long-term antibiotic therapy received within the past month * Immunosuppressive/immunomodulatory treatment within the past 3 months * Person under guardianship or curatorship, under judicial protection, or deprived of liberty by judicial or administrative decision * Patients covered by State Medical Aid (AME) * Pregnant or breastfeeding women Controls: Objection to the research