Association Between Photodynamic Therapy Session Number and Psychosexual Well-Being in Vulvar Lichen Sclerosus: A Correlation Analysis

Background: Vulvar lichen sclerosus (VLS) represents a chronic inflammatory dermatosis associated with significant symptoms, architectural changes of the vulva, and impaired quality of life (QoL). Photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) has emerged as a potential therapeutic option for patients with disease refractory to standard topical treatments. The aim was to investigate whether PDT is associated with QoL and sexual functioning outcomes. Methods: Patients with refractory VLS were treated with PDT using a 10% 5-ALA nanoemulsion applied to affected areas and covered with an aluminum foil occlusive dressing. Participants underwent between one and six PDT sessions, each consisting of 10 min of LED illumination (37 J/cm2, approximately 77 mW/cm2), delivered at 4–6-week intervals. Outcomes were assessed using the Dermatology Life Quality Index (DLQI; n = 37) and the Female Sexual Function Index (FSFI; n = 20). Results: A greater number of PDT sessions was associated with better quality of life (lower DLQI score; tau = −0.5831, adjusted p = 0.0002) and improved overall sexual function (higher FSFI score; tau = 0.5562, adjusted p = 0.0143). Analysis of individual FSFI domains showed significant positive correlations for desire (tau = 0.5125, adjusted p = 0.0166), arousal (tau = 0.4734, adjusted p = 0.0201), orgasm (tau = 0.4878, adjusted p = 0.0201), and satisfaction (tau = 0.5075, adjusted p = 0.0166), while lubrication (tau = 0.2019, adjusted p = 0.3960) and pain (tau = 0.0407, adjusted p = 0.8707) were not significantly associated with the number of PDT sessions. Conclusions: This study demonstrates an association between a higher number of PDT sessions and better quality-of-life and sexual-function outcomes in patients with refractory VLS. The findings support an individualized treatment approach guided by clinical response rather than fixed session limits. Future studies should focus on optimizing treatment protocols and identifying predictors of response.