Why led was effective for skin disease?

Different wavelength formed different light color ,

in medicine , 400nm to 600nm was a common light . 400nm uv led is the role of bactericidal anti-inflammatory. Because of the skin can absorbs wavelength of light . uv led strip resolve the germs . and Regulate sebum secretion, prevent skin disease; suitable for combination and oily skin.
used both 400nm and 600nm is best. the main function of 600nm light is treating blood-stasis syndrome. the red light can promote the reconnection of the blood circulation of flap and increase the survival length of the blood cell . it also can increase the permeability of blood capillary. synthesis metabolism to speed up, Repair the expansion of capillary vessels .