Revised: December 26, 2013
Accepted: March 13, 2014
Published online: May 2, 2014
Photodynamic therapy (PDT) is a relatively new therapy in dermatology that uses the topical application of a porphyrin derivative to selectively destroy a cutaneous target. The action is implemented by the application of a specific light frequency. The ability of porphyrin to selectively target tumor tissue has been known since the 1960s. In the late 1970s, the underlying mechanism was defined, and Dougherty’s discovery of the first chromophore led to the production and commercialization of Photofrin®. Many other chromophores that can act as photosensitizers have been studied since then, with aminolevulinic acid currently the most commonly used chromophore in clinical practice. PDT is simple, minimally invasive and can be administered on an outpatient basis. The efficacy of PDT has been proven for actinic keratosis, Bowen’s disease and basal cell carcinoma; another of its well-known applications is the treatment of photoaging. Indications for its use are continuously increasing, and promising results are reported for various skin diseases. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence.
Core tip: Photodynamic therapy (PDT) with aminolevulinic acid is a relatively new therapy in dermatologic practice, and the indications for PDT are increasing continuously. PDT is based on the topical application of a porphyrin derivative followed by exposure of the treated area to a specific wavelength of light to selectively destroy a cutaneous target. A thorough knowledge of the mechanism of action of the treatment and its effects are necessary to provide the patient with an appropriate assessment and indication. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence, according to the European Guidelines.