Increased Neutrophil-to-LymphocyteRatio as a Marker of Systemic Immunity in Lichen Sclerosus

Introduction: Lichen sclerosus (LS) is a chronic inflammatory dermatosis traditionally considered a localized condition, yet associations with autoimmune comorbidities and circulating autoantibodies suggest possible systemic immune involvement. The neutrophil-to-lymphocyte ratio (NLR) is an inexpensive biomarker of systemic inflammation and frailty, but its role in LS has not been investigated. Aims: To evaluate NLR values in patients with LS and assess whether LS is associated with systemic inflammatory changes. Methods: This single-center retrospective observational study analyzed anonymized laboratory data from patients diagnosed with LS at IDI-IRCCS (Rome, Italy) between January 2020 and January 2025. Full blood count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), age, and sex were collected. Patients were subdivided into three age groups (<65, 65–74, ≥75 years). Welch’s ANOVA and t-tests assessed group differences; chi-square tests examined NLR frailty-range distribution; Pearson correlations evaluated associations with CRP and ESR. Results: A total of 631 samples were included. Mean NLR was 2.34 ±1.36, increasing significantly with age (P=0.02). Approximately one third of patients fell within frailty-associated NLR ranges. Among adults <65 years, mean NLR (2.17 ±1.00) was significantly higher than in two healthy control cohorts (1.85 ± 0.64 and 1.65 ± 1.96; both P<0.01). NLR correlated moderately with ESR (r=0.47) and modestly with CRP (r=0.36). Conclusions: LS is associated with higher NLR values than those observed in healthy controls, indicating mild systemic inflammation. These findings support the concept that LS may not be exclusively localized but may involve broader immune dysregulation. NLR may help identify LS patients with potential systemic involvement, although prospective validation is required.