Side note: I tried to find out wtf the original injury was. After some doing, I managed to track down the un-captioned pic to imgur. Attempted to search google for the image. Google apparently can't handle whatever is going on with this guy, because it did not find the image. It DID, however, find a bunch of images it claimed were of "very similar results."
Sweet potatoes. Every single picture was of sweet potatoes.
look at the red you can see the thickness of the skin is pretty thick. id put my money on him having Vitiligo a disease that causes white patches and its just a coincidence that he got hurt in that specific spot. any chemicals or fire would leave the arm red, pink, or burnt black or skin sloughing off. if he was a white guy it would look like a slip and fall on dirt or something like that. the only thing im not sure of is i don't see any hair on the arm. part of the disease? or maybe this guy just doesn't have hair on his arms.
Sweet potatoes. Every single picture was of sweet potatoes.