Photodynamic Therapy in the Dermatological Field and Enhanced Cutaneous Absorption of Photosensitizer

The combination of light and chemicals to treat skin diseases is widely practiced in the field of dermatology, and has led to the concept of photodynamic therapy in recent years. In PDT for skin cancer, 5-aminolevulinic acid is applied topically to the affected area to be absorbed percutaneously through passive diffusion, and typically requires 4–6 h before performing PDT. In this study, we attempted to reduce the absorption period in PDT by ionizing ALA using direct current pulsed iontophoresis and Bowen’s disease. In all subjects, protoporphyrin IX production was confirmed after iontophoresis, and its production levels were comparable to the conventional occlusive dressing technique. Skin biopsies from the treated lesion showed the disappearance of tumour cells.