Clinical response and time to improvement with 308-nm excimer laser therapy in scarring alopecia: a retrospective cohort study.

PURPOSE: Excimer laser therapy, a 308-nm narrowband UV-B modality, has shown promise in inflammatory dermatoses, but remains understudied in scarring alopecia (SA).

MATERIALS AND

METHODS

We conducted an IRB-approved retrospective study of adults with SA treated with excimer therapy to characterize clinical outcomes, response timelines, and treatment patterns.

RESULTS

Most patients had lichen planopilaris or frontal fibrosing alopecia and received excimer as adjunctive therapy following prior multimodal treatment. Initial treatment was administered twice weekly, with a mean starting dose of 235.7mJ/cm2. After a mean of 3.4 months, 60% of patients reported subjective improvement in hair or hairline appearance. Symptomatic improvements were observed in scalp pain (100%), burning (75%), and pruritus (50%), generally within two to six months. Signs of inflammation, including perifollicular hyperkeratosis and erythema, improved in 83% of affected patients. Trichoscopic measures of hair density and shaft caliber remained stable, suggesting disease stabilization without accelerated follicular loss. Adverse effects were common but mild, including erythema, burning, and pain, and did not lead to koebnerization.

CONCLUSIONS

Overall, excimer therapy was well-tolerated and associated with meaningful clinical and symptomatic improvement. These findings support excimer therapy as a potentially effective adjunctive treatment for inflammatory control and stabilization in SA, with response typically occurring within the first several months of therapy.