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

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. 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. 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. At day 3, day 7, and day 30 post treatment, vegan group showed higher total LSR score ( = .008,  < .001,  < .001, respectively), highlighting higher edema and vesiculation at day 3 ( < .001,  = .002, respectively), erythema, desquamation, edema, and vesiculation at day 7 ( < .001,  < .001,  < .001,  < .001, respectively) and erythema and desquamation after 30 days ( < .001,  < .001, respectively). The difference of complete skin healing was statistically significant ( < .001). 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.