PO:25:083 | Overlap between Sjögren’s syndrome and lichen sclerosus: beyond coincidence?

Background. Lichen sclerosus (LS) is a chronic, immune-mediated inflammatory condition that predominantly affects mucocutaneous areas, particularly the anogenital region. Although the etiopathogenesis of LS remains poorly understood, autoimmune, genetic, infectious, and traumatic mechanisms have been hypothesized.¹ Large-scale epidemiological studies are limited, but the estimated prevalence in the general population ranges from 0.05% to 0.3%. ²,³ In Italy, LS is classified among rare diseases (prevalence 5/10,000; exemption code RL0060). LS has been associated with several dermatological and immune-mediated conditions, including Hashimoto’s thyroiditis, psoriasis, vitiligo, alopecia areata, ulcerative colitis, systemic lupus erythematosus (SLE), and systemic sclerosis. However, the relationship between LS and systemic autoimmune diseases warrants further investigation. Although some case reports have described overlap between LS and Sjögren’s disease (SjD), this potential association remains poorly explored.   Outcome: To further investigate the possible overlap between LS and SjD.   Materials and Methods: Medical records of patients with SjD and non-Sjögren sicca syndrome consecutively evaluated at the Sjögren Clinic of our Rheumatology Unit over the past 12 months were reviewed. During each visit, patients were specifically asked whether they had ever received a diagnosis of LS. Those reporting a prior diagnosis of LS were subsequently re-evaluated to confirm the diagnosis.   Results. A total of 378 patients with SjD (13 males, 365 females; mean age 55 years, range 24–79; mean disease duration since diagnosis 3.7 years) and 99 subjects with non-Sjögren sicca (6 males, 93 females; mean age 56.3 years, range 34–72; mean symptom duration 3.12 years) were included. Among patients with SD, 7/378 (1.8%) female patients had a confirmed diagnosis of LS (mean age 46.8 years, range 37–55). None of the subjects with non-Sjögren sicca had LS.   Conclusions. Although no statistically significant differences were observed between SjD and non-Sjögren sicca, the prevalence of LS among patients with SjD was higher than that reported in the general population. This observation supports the hypothesis of shared etiopathogenic mechanisms, likely immune-mediated, as further suggested by the reported occurrence of SjD in approximately 1.5% of patients with LS. This comorbidity should always be investigated in patients with SjD. References Singh N, Ghatage P. Etiology, clinical features, and diagnosis of vulvar lichen sclerosus: a scoping review. Obstet Gynecol Int. 2020; 2020:7480754. Murphy R. Lichen sclerosus. Dermatol Clin. 2010;28(4):707-15.  De Luca DA, Papara C, Vorobyev A, Staiger H, Bieber K, Thaçi D, Ludwig RJ. Lichen sclerosus: The 2023 update. Front Med (Lausanne). 2023;10:1106318. Guttentag A et al. Australas J Dermatol. 2025;66:135-141. Shiboski CH, Shiboski SC, Seror R, Criswell LA, Labetoulle M, Lietman TM, et al. The 2016 American College of Rheumatology and European League Against Rheumatism classification criteria for primary Sjögren's syndrome were developed through a consensus and data-driven methodology that involved three international patient cohorts. Arthritis Rheumatol. 2017;69(1):35-45.