Photodynamic therapy (PDT) is a new and effective treatment modality for acne. Its mechanism of action is based on a chemical reaction that occurs in skin cells affected by the bacteria that causes acne, after this skin is treated with a photosensitizing substance, producing a therapeutical response when exposed to a certain type of light with a particular wavelength.

This treatment makes possible to reduce propionibacterium acnes and also causes destruction of the affected sebaceous glands, causing a decrease in the production of sebum and other inflammatory cells that produce acne.

Photodynamic therapy (PDT) is an ideal treatment alternative for patients who are not candidates to be medicated with antibiotics or retinoids, and also for those who have not shown improvement with other kind of treatments.

The most used photosensitizing substance is amino-levulinic acid (ALA), and the lights used include red light, blue light, intense pulsed light, laser diode and sunlight among others.