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The status of laser ablation for vulvar lichen sclerosus remained unclear following two small randomized clinical trials that produced conflicting results.

In one study, fractionated carbon dioxide (CO₂) laser treatment led to significantly greater improvement compared with a topical steroid, according to assessment by the Skindex-29 dermatology qualify-of-life index. However, the trial was powered to detect a difference of 16 points on the Skindex-29, and the data showed a difference of 10.9 points.

After adjustment for prior steroid use, the difference in Skindex-29 score remained statistically significant only for patients with prior steroid exposure, reported Linda Burkett, MD, of Magee-Womens Hospital of the University of Pittsburgh Health System, and colleagues in .

In the , there was no difference in histopathology scores with active versus sham laser treatment, said Andrew Goldstein, MD, of the Centers for Vulvovaginal Disorders in Washington, D.C., and co-authors.

An noted several limitations to the studies: a significant placebo effect in both control groups, different scoring systems to assess change in disease status, and historically poor compliance with medical treatment.

"On the surface, fractionated CO₂ laser appears to provide symptomatic improvement for patients; however, given the considerable placebo effect, lack of histologic improvement, posttreatment photographs, and significant out-of-pocket cost for patients, this treatment will not replace ultrapotent topical steroids as first-line therapy for vulvar lichen sclerosus in my practice," concluded Melissa Mauskar, MD, of the University of Texas Southwestern Medical Center in Dallas.

An uncommon , vulvar lichen sclerosus causes significant architectural changes to the labia minora, clitoris, and anus, often accompanied by itching, pain, and dyspareunia. About affected by vulvar lichen sclerosus develop vulvar cancer.

Many patients are not adequately treated, and evidence suggests that appropriate treatment results in symptom resolution, repigmentation, and return to normal skin texture, which is associated with a reduced risk of vulvar cancer, noted Burkett's group. The historical standard of care is topical clobetasol propionate.

Laboratory and histopathologic studies have suggested CO₂ laser energy may induce molecular changes that could result in favorable effects on tissue affected by vulvar lichen sclerosus. Small case series have shown symptomatic improvement in most patients following treatment with a CO₂ laser.

Laser vs Topical Steroid

Burkett and colleagues compared CO₂ laser treatment and topical clobetasol propionate in postmenopausal patients with vulvar lichen sclerosus. The randomized study included 27 patients treated with the laser and 25 allocated to the topical steroid.

Patients assigned to the laser had three treatment sessions 4 to 6 weeks apart. Those assigned to topical clobetasol applied the ointment nightly for 1 month, then three times weekly for 2 months, followed by as-needed application to the end of the study. Patients on topical steroids at enrollment completed an 8-week washout period before beginning randomized therapy. The primary outcome was the mean change in Skindex-29 score at 6 months.

The patients had a mean age of 64.5 and had been menopausal for an average of 17 years. Median duration of lichen sclerosus was about 6 months, half the patients had prior clobetasol exposure, and almost half were on estrogen therapy.

Mean baseline Skindex-29 scores were 29.70 for patients previously treated with topical clobetasol and 33.11 for those without prior exposure. The primary analysis showed a mean change from baseline of -16.83 in the laser group and -5.92 in the clobetasol arm (mean difference 10.91, P=0.007). In addition, results favored the laser group for the emotion (12.86, P=0.011), symptoms (16.12, P=0.002), and function (5.35, P=0.210) domains.

Neither treatment was associated with serious safety or adverse events, the authors said.

Active vs Sham Laser

The trial comparing active versus sham laser treatment involved 37 patients who had a mean age of 59 and a lichen sclerosus duration of 8 years. All patients abstained from systemic and topical therapy for 4 weeks prior to beginning randomized treatment. Patients in both arms had five treatment sessions over 24 weeks, reported Goldstein's team.

In the active treatment arm, patients received escalating doses of laser energy, increasing from 18 to 26 watts of power and dwell time from 800 to 1,000 microseconds (µS). Sham treatment was standardized to 4 watts of power and 400-µS dwell time. The primary outcome was the change in histopathology scale score from baseline to 24 weeks.

The histopathology scale score ranges from 0-6 (higher score = worse), and the baseline mean score was 4.2-4.3 in the active and sham treatment groups. Active laser treatment resulted in a reduction of 0.2 in score from baseline (95% CI -1.1 to 0.80, P=0.74). In those who received sham treatment, there was an increase of 0.1 from baseline (95% CI -0.90 to 1.0, P=0.91).

Patients in both arms had significant improvement in the secondary endpoint of clinical symptom score, which decreased by 7.10 points in the active-treatment arm (P=0.02) and 4.80 points in the sham-treatment arm (P=0.04).

"This study showed that there was no meaningful improvement in the histopathologic changes of vulvar lichen sclerosus with fractionated CO₂ laser therapy compared with sham treatment, indicating that fractionated CO₂ is not an effective monotherapy for vulvar lichen sclerosus," wrote Goldstein and colleagues.

"An additional significant finding is that women in both the active treatment arm and sham treatment arm experienced a statistically significant improvement in symptoms of vulvar lichen sclerosus, illustrating a large placebo effect and highlighting the need for randomized, controlled trials to obtain meaningful data for the treatment of vulvar lichen sclerosus," they added.