What Is Going On With Lou Reed's Mouth?

    Has he been eating a solid diet of green apple Jolly Ranchers? I need to know what causes this so I will never do it.

    Here is Lou Reed at a recent event:

    Wait, what's going on with this mouth?

    What IS this yellowy-green stain in the corners?

    Did he just drink a wheatgrass smoothie? Moutain Dew? Is that from nicotine?

    Seriously, WHAT CAUSES THIS?