Photodynamic therapy for aesthetic-cosmetic indications.

Photodynamic therapy (PDT) is a well-established, non-invasive treatment for a variety of dermatologic disorders, including actinic keratosis. Furthermore, PDT results in marked improvements in the signs of skin aging, although currently there are no standardized guidelines for PDT in skin rejuvenation. Two types of PDT are available: conventional-PDT (c-PDT) and the newly introduced daylight-PDT (DL-PDT). Both require a topical photosensitizer, a light source and oxygen, and both are comparable regarding safety and efficacy for treatment of photo-induced skin aging. Treatment is particularly effective for improvement of fine wrinkles, skin roughness, actinic elastosis and mottled hyperpigmentation. The most widely studied topical sensitizers used in PDT are 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL). A range of pre-treatment procedures help improve skin absorption of the photosensitizer and lead to significantly improved efficacy. A variety of activating light sources can be used for c-PDT, while DL-PDT uses natural daylight, making it easier to treat larger areas of photodamaged skin. A major limitation of c-PDT is significant treatment-related pain, but DL-PDT has proved to be an almost pain-free procedure. Treatment duration is based on individual patient need but most patients receive 2 to 3 treatment cycles, with results fully evident 3-6 months post-treatment. PDT for aesthetic-cosmetic treatments has established its value in modern procedural dermatology as mono- or combination therapy. A major, unique advantage of PDT is that it is a non-invasive treatment that effectively rejuvenates photodamaged skin, while successfully treating a range of dermatologic conditions, including prevention and therapy of pre-cancerous actinic keratosis.