Photodynamic therapy for actinic keratosis in vegan and omnivore patients: the role of diet on skin healing.

Background: Photodynamic therapy (PDT) is an approved and effective treatment for actinic keratosis (AK). The time of complete skin healing is estimated to range between 5 and 10 days, but the role of nutrition in influencing it has never been evaluated. Objective: The aim of this study was to compare the time of skin healing and side effects in omnivores and vegans treated with PDT for AK. Materials and methods: Thirty omnivore and thirty vegan patients, treated with PDT for AK, were enrolled. Side effects, according to local skin response (LSR) score, were compared after 3, 7, and 30 days; the time of complete skin healing was recorded. Results: At day 3, day 7, and day 30 post treatment, vegan group showed higher total LSR score (p = .008, p < .001, p < .001, respectively), highlighting higher edema and vesiculation at day 3 (p < .001, p = .002, respectively), erythema, desquamation, edema, and vesiculation at day 7 (p < .001, p < .001, p < .001, p < .001, respectively) and erythema and desquamation after 30 days (p < .001, p < .001, respectively). The difference of complete skin healing was statistically significant (p < .001). Conclusions: The present study suggests that diet may have a prognostic and predictive role on PDT outcomes in term of side effects and time of skin repair.