This observational study aims to evaluate routine treatment outcomes in men with lichen sclerosus (LS), including a long-term follow-up to assess disease progression and histopathological changes. The study also investigates potential risk factors for LS and the disease's impact on quality of life and sexual health.

Lichen sclerosus (LS) is a chronic inflammatory and scarring dermatosis with a predilection for the anogenital area. While both sexes can be affected, this study focuses on men, in whom LS can cause phimosis and may require circumcision. Topical corticosteroids are first-line treatment, but there is a lack of long-term studies evaluating the efficacy of circumcision in male LS. In addition, risk factors and the impact of LS on quality of life and sexual health are insufficiently studied.

This observational cohort study aims to follow male patients with LS over time to assess treatment outcomes, disease progression, and the potential development of epithelial atypia. Patients aged 18 years or older, Swedish-speaking, and diagnosed with LS will be recruited from both the urology and dermatology departments in Västerbotten County, Sweden. At the urology department, patients undergoing circumcision for phimosis will be included; at the dermatology department, all men diagnosed with LS will be invited to participate. All participants will provide written informed consent and will receive treatment according to standard clinical routines and national or international guidelines.

Participants will complete a standardized questionnaire regarding symptoms, quality of life, and sexual health. A control group of age-matched, Swedish-speaking men without genital symptoms will also complete the same questionnaire once but will not be followed longitudinally. For exploratory analyses, patients recruited from the urology department will also provide biological samples (e.g. foreskin, urine, feces) at baseline to facilitate future investigations of microbiome composition and metabolic profiles.

Inclusion Criteria for patients with LS (LS Urology and LS dermatology):

• Biologically male
• ≥18 years old
• Referred to the dermatology department or the urology department in Västerbotten and diagnosed with LS.
• Must be able to read and write Swedish to fill in questionnaire and informed consent.

Inclusion criteria for control group "Controls - Urology":

• Biologically male
• ≥18 years old
• Phimosis without LS, treated with circumcision at the urology department in Västerbotten
• Must be able to read and write Swedish to fill in questionnaire and informed consent.

Inclusion criteria for control group "Controls - General Population":

• Biologically male with male genitalia
• ≥18 years old
• No genital symptoms
• Must be able to read and write Swedish to fill in questionnaire and informed consent.

Exclusion Criteria for all groups:

• Age under 18 years old
• Not able to read and write in Swedish.
• Unable to leave an informed consent to participate.

This study includes adult men (≥18 years old), Swedish-speaking, recruited from the dermatology and urology departments in Västerbotten County, Sweden. Participants with a clinical diagnosis of lichen sclerosus (LS) will be recruited from both departments. From the urology department, additional participants undergoing circumcision for phimosis will be included; this group may include both patients with and without LS, as confirmed by histopathological examination of the foreskin. An age-matched control group of men without genital symptoms will also be included. All participants must be able to provide informed consent.

Data on group level will be shared upon request. Sharing individual participant data must be investigated to make sure it is compliant with Swedish laws and EU regulations.