Microbial Species in Deep Tissue Lesions of Stage III Hidradenitis Suppurativa: A Retrospective Observational Study

Background Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful nodules, abscesses, and sinus tract formation. While dysbiosis of the skin microbiome has been implicated in HS pathogenesis, most studies focus on surface flora, leaving the microbial composition of deep tissue lesions poorly characterized, particularly in surgically managed Hurley stage III disease. This study investigates the subcutaneous microbiome of stage III HS requiring surgical intervention, with the goal of identifying microbial patterns and their associations with patient-specific clinical features. Methods A retrospective chart review of 49 patients undergoing surgical excision for HS was performed. Intraoperative subcutaneous tissue samples were cultured under aerobic and anaerobic conditions. Demographic, clinical, and treatment data were analyzed for associations with microbial findings. Results Prevotella species were significantly associated with type II diabetes (OR 16.00) and prior antibiotic use (OR 3.586). Corynebacterium species were more frequently isolated in older patients and the perineal and chest regions. Gram-negative rods correlated with prior antibiotic exposure (OR 14.143), while gram-positive cocci were associated with smoking (OR 5.500). Microbial profiles varied significantly by anatomical site, suggesting location-specific colonization. Conclusions The subcutaneous microbiome in stage III HS remains poorly characterized due to the historical focus on surface lesions and non-surgical populations. Our findings highlight distinct microbial profiles within deep tissue that are influenced by comorbidities, antibiotic exposure, and anatomical sites. Plastic and reconstructive surgeons have a critical role in managing advanced HS and this study provides evidence for targeted perioperative antimicrobials to reduce postoperative complications and improve surgical outcomes.