Basic principle : melanin Generation
Visible pigmentation of the skin, hair, and eyes depends primarily on the presence of melanin in those tissues. Melanin are produced by specific cells called melanocytes. Not only is the type of melanin produced important, but also its eventual distribution in the tissue dramatically affects visible color, which ultimately determines the functions of the pigment, such as photo protection (Gilchrest, 2011).
Hyperpigmentation can be caused by sun damage, inflammation, or other skin injuries. Many forms of hyperpigmentation are caused by an excess production of melanin. Hyperpigmentation can be diffuse or focal, affecting such areas as the face and the back of the hands. Another form of hyperpigmentation is post inflammatory hyperpigmentation.
How does it work
PIH (post inflammatory hyperpigmentation) is a frequently encountered problem and represents the sequelae of various cutaneous disorders as well as therapeutic interventions especially on Asian and dark complexion patients. A preventative and complementary approach to thermal laser induced PIH using LED therapy is possible. According to unpublished work performed in our laboratory, the use of LED 660 nm therapy can prevent or treat PIH. (Barolet, 2008)