Photodynamic therapy in dermatology: established and new indications.

Photodynamic therapy (PDT) is internationally established as an approved treatment option for in situ forms of keratinocytic skin cancer (actinic keratoses, Bowen's disease, basal cell carcinoma). For these indications, there are standardized treatment protocols using narrow-spectrum light sources or (artificial) daylight, the use of which is associated with successful healing, a low rate of lesion recurrence, and a very good cosmetic result. Daylight PDT is superior to conventional PDT in terms of significantly less pain and associated higher patient acceptance. Newer indications, for which no approval has yet been granted, but which nevertheless have sufficient evidence of efficacy according to the study situation, are inflammatory (lichen sclerosus, acne) and infectious dermatoses (viral warts, cutaneous leishmaniasis, atypical mycobacteriosis). In addition, PDT is increasingly being used in aesthetic dermatology with the aim of skin rejuvenation.