Aim of this study is to evaluate the therapeutic effect of the laser treatment in vulvar LS, mainly the reduction of existing symptoms. As measured by visual analogue scale (VAS) symptoms as itching, burning, pain will be determined six weeks after the last laser treatment. Secondary endpoints will be sexual function measured with the female sexual function index (FSFI) and the vulvar skin changes measured by the Lichen score (LS).

Regular photo-documentation of the treated skin will demonstrate a potential change of the tissue.

Lichen sclerosus (LS) is a vulvar dermatosis that changes the skin to white plaques (lichenification), less elasticity (sclerosis) and the tissue shows contractions with erosions and fissures. Gold standard for the therapy of LS is the topical application of ultrapotent corticosteroids, proper treatment reverses the underlying inflammation of LS, reduces symptoms as itching and burning and may lower the risk of getting vulvar cancer. While useful, steroid creams may have serious side effects that include thinning of the skin, fungal infections, and lowering the immune system. Treatment with the fractional microablative carbodioxide Laser is a minimal invasive procedure. In the literature only few published reliable data in laser therapy of vulvar skin diseases can be found, there is only one survey especially for the treatment of vulvar LS. However, published data show a potential that justifies the use of this method for the indication in treating LS.

Aim of this study is to evaluate the therapeutic effect of the laser treatment in vulvar LS, mainly the reduction of existing symptoms. But there is little comparable data, so the necessary frequency of treatment, the dose of laser application, additional use of corticosteroid or the sustainability is not yet known

Aim of this study is to evaluate the therapeutic effect of the laser treatment in vulvar LS, mainly the reduction of existing symptoms. As measured by visual analogue scale (VAS) symptoms as itching, burning, pain will be determined six weeks after the last laser treatment. Secondary endpoints will be sexual function measured with the female sexual function index (FSFI) and the vulvar skin changes measured by the Lichen score (LS).

Regular photo-documentation of the treated skin will demonstrate a potential change of the tissue.

Primary endpoint will be the outcome after laser application, the change in symptoms between both groups. As secondary endpoint it is important to see, weather sexual functions will be influenced in this therapy.

The study is designed as a randomized placebo-controlled study.

Inclusion criteria: All patients are treated in the dysplasia unit of the university gynecological hospital of Bern. They have a histological confirmation of LS or a clinical diagnosis of LS according to the lichen-score. Informed consent will be oral and written. The minimum age is 18 years

Exclusion criteria: Pregnancy, local bacterial or parasitical infection, others severe dermatosis, Lichen-score < 5, vulvar cancer

All women who qualify for the study and signed informed consent will be grouped by computer-controlled randomization. All of them are informed, that they have to take part in three sequent sessions of treatment in the interval of three weeks and the defined follow -ups after six and twelve weeks.

The session starts with the application of an ointment for a local anesthesia in the vulvar region. Meanwhile they will answer the questionnaires (VAS for recording the vulvar symptoms, FSFI for the documentation of the sexual function, another questionnaire to evaluate the present situation).

After about 20 minutes the gynecologist will start the examination with a photo documentation of the vulva, then the laser application of the vulva is following. After the treatment a cream of silversulfadiazine (Flammazine) will be applied.

All personal data of the patients will be anonymized. The study specific intervention is an application of laser radiation on the vulvar skin.

The used laser instrument for this specific intervention is a microablative fractional CO2 laser designed as SmartXide Touch C60, CO2 laser system for MonaLisa Touch, DEKA, Florence. For the vulvar use the Hi-Scan V2LR scanning system has to be connected.

The laser setting is: Power 24 W, exposure time 400 microsec, density 6,4 %, pulse energy 23,2 mJ, fluenz 1,18J/cm2, emission mode DP, DOZ Dwell 400, DOT spacing 1000.

Projected are three sequent sessions in three weeks intervals. Application time takes approximately five minutes for the whole vulvar skin.

The study will compare two groups of patients, both fulfil the same criteria as a histological confirmation of LS or a clinical diagnosis of LS according to the lichen-score. They will be grouped by computer-controlled randomization in an active group and in a placebo group.

The active group will be treated by radiation with a real dose: power 24 W, exposure time 400 microsec, DOT spacing 1000.

The placebo group will be treated with a sham dose: power 0, 5 W, exposure time 400 microsec, DOT spacing 1000.

Both groups undergo the same procedures, they will have the same application time and application area. Except of the different radiation dose they undergo the same regimen.

Inclusion Criteria:

• Women aged >18 years
• Women with histological assured or clinical confirmed Lichen sclerosus (Lichen score > 5)
• Informed Consent as documented by signature (Appendix Informed Consent Form)

Exclusion Criteria:

• Unable to read or understand study patient information document
• Patients with a legal guardian
• Refusal to participate
• Missing signed consent
• Pregnancy and lactation
• Proven bacterial or parasitic infection (clinical examination and/or vaginal wet mount)
• Vulvar cancer

Study enrollment possible for all participants with vulvar lichen sclerosus