PDT helps treat bacterial, fungal, and viral infections. It also treats acne, rosacea, and other skin conditions such as keloids and hypertrophic scars. Typically, s series of 8-10 treatments will be required over a 4-6 week period. Given the variety of treatments available and the number of sessions you need, you could be seeing between $100 up to $4000, and that's a single treatment!