Lasers alleviate acne.

Propionibacterium acnes (P. acnes) and sebaceous glands are involved in the pathogenesis of acne. Although often effective, traditional therapies can have drawbacks, such as photosensitivity, other toxicities, polypharmacy and frequent dosing. Lasers have been studied to seek a solution that may overcome these disadvantages. Lasers and other light therapies target the wavelengths of the porphyrins in P. acnes to induce thermal damage that causes the bacterium's destruction. Pulsed-dye laser (PDL) or a system of light pulses and heat with wavelengths between 430 and 1100 nm are both efficacious. The 1450-nm diode laser targets sebaceous glands and is also effective. Topical indocyanine green (ICG) photodynamic therapy (PDT), using the near-infrared (NIR) laser, targets either P. acnes or sebaceous glands. ICG-PDT has fewer adverse effects than aminolevulinic acid-PDT. Lasers are still a relatively new therapy for acne and may be best used in an adjuvant role.