The microbiome of tunnels in hidradenitis suppurativa patients

Abstract Background Hidradenitis suppurativa ( HS ) is a chronic inflammatory skin disease defined by recurrent nodules, tunnels and scarring involving the intertriginous regions. Recent next‐generation sequencing ( NGS ) studies suggest genera such as Prevotella spp., Peptoniphilus spp. and Porphyromonas spp. are associated with chronic and early HS lesions. However, a systematic investigation of the bacterial microbiome in HS tunnels remains unexplored using NGS . Objective We aimed to investigate the bacterial composition of the luminal white gelatinous material found in HS tunnels using NGS . Methods An exploratory study of patients with diagnosis of HS ( n = 32) with tunnels. The tunnels were present either in the groin ( n = 17) or in the axilla ( n = 15). During deroofing of the tunnels, a sterile E‐swab was taken of the luminal gelatinous material. The samples were investigated using NGS targeting 16S ribosomal RNA . Results The skin microbiome was characterized in 32 HS patients. Overall, five microbiome types were identified: Porphyromonas spp. (type I), Corynebacterium spp., (type II ), Staphylococcus spp. (type III ), Prevotella spp. (type IV ) and Acinetobacter spp (type V). Porphyromonas spp. (type I) and Prevotella spp. ( IV ) were the most frequent genera found the tunnels. Conclusion This study points to a potential association between the presence of certain anaerobic bacteria ( Porphyromonas spp., Prevotella spp.) and HS tunnels. It may be speculated that these two genera are associated with the pathogenesis in HS either as drivers or as biomarkers.