Penile Microbiome in Histopathologically Confirmed Lichen Sclerosus: A Comparative Study of Urethral and Preputial Swabs

Purpose The study aimed to analyse the microbial compositions of patients with LS compared to those with other penile conditions, in an attempt to answer the pressing question considering the ethiology of penile lichen sclerosus(LS) and a potential role for the microbiome in its pathogenesis. Methods In this prospective single-centre study, 79 uncircumcised male patients undergoing circumcision for phimosis were enrolled between January 2023 and April 2024. Foreskin and urethral swabs were obtained prior to surgery to isolate Candida, aerobic, and anaerobic microorganisms and sexually transmitted pathogens. Patients were categorised into LS(n=52) and non-LS(n=27) groups based on histopathological findings. Results No statistically significant differences were observed in the prevalence of specific bacterial or viral pathogens between the LS and non-LS groups. The most common commensal organisms were Staphylococcus coagulase-negative(46% and 37% respectively) and Corynebacterium spp.(27% and 15% respectively), whereas Enterococcus faecalis (37%) and Escherichia coli(15%) were the most frequent pathogens in LS group, and Streptococcus agalactiae(22%) was the most abundant pathogen in non-LS group. HPV was detected in 5.8% of patients with LS and in 11% of patients without LS. There were no statistically significant differences in CRP levels and BMI, however age was significantly higher in the LS group(p=0.0004). Conclusions Our study demonstrated no significant association between specific microbial or viral profiles and penile lichen sclerosus. However, the role of the penile microbiome in the pathogenesis of LS remains inconclusive and the need for larger, standardised studies to clarify the potential role of the microbiome in LS pathogenesis lives on.