ABSTRACT
Already at the time of the discovery of its mechanism and coining the term “photodynamic” in the early 20th century, dermatologic disorders had been treated with photodynamic therapy (PDT) by von Tappeiner in Germany and Finsen in Norway. After this, it took about 70 years-until the works of Tom Dougherty-for the idea of using PDT to be picked up again (Dougherty 1984). The main drawback of early PDT was the use of systemic photosensitizers like Photofrin and hematoporphyrin derivative (HPD), which led to a very long photosensitivity of the treated patients. This made systemic PDT not very attractive for the treatment of small and localized cutaneous lesions.
