Propionibacterium acnes in the pilosebaceous unit and follicular inflammation are two of the four main pathogenesis of acne. In addition, if we can decrease the number of sebaceous glands, we can improve acne. Any method which does not disrupt systemic hormonal levels is also beneficial. If we can control these trigger factors, we can reduce the severity of acne, or improve acne.
Phototherapy is a noninvasive, out-patient procedure with a proven efficacy in acne treatment. It involves the activation of photosensitizing agent (endogenous synthesis or stimulating from exogenous agents) by visible light to produce activated oxygen species within a target area, resulting in their destruction [27,28].