Does PDT (Photodynamic Therapy) Work on Back Acne?

Yes, PDT does work on the back. It may take more than one treatment, depending on the lasers and light devices used.  I would see a board-certified dermatologist who specializes in lasers and PDT to perform the treatment as there are things that can be done to maximize results. Good luck!

Photodynamic therapy (PDT) is FDA approved to treat actinic keratoses, or pre-cancers.  Dermatologists use the treatment off-label (not FDA approved) to treat acne.  It is a safe and effective treatment.  A chemical called levulan is applied to the area to be treated and sits on the skin for a certain amount of time.  The skin is then exposed to blue light in the office.  Following the treatment, there may be pain, swelling, and temporary worsening of the acne.  Sunlight must be avoided for 72 hours following the treatment.  Several sessions are required for best results. 

PDT treatments for acne are all considered 'off label use' hence are not FDA approved nor covered by insurance.  All that being said, the levulinic acids used in the topical medication applied prior to light exposure are strongly absorbed by sebaceous glands, where acne occurs.  By shutting down these oil glands, the entire acne process will diminsh or stop..You need several treatments spaced at least 2 weeks apart.  Be prepared for some tenderness, swelling and light sensitivity to the treated areas.  All ALAs work, but right now the choices are Kerastick, Metvix and Allumera.  My personal preference for moderate severe acne, where even Accutane could be a choice is Metvix follwed by exposure to Red Diode Light rather than Blue Light.  Good luck!