I have a brown spot underneath the nail on my left big toe. That s the only toe that has a spot. I ve had previous fungal infection in both big toes but they went away. This spot appeared all of a sudden. I didn t notice until last week. It doesn t seem to be getting any bigger but it s quite unusual. No pain, no itching, however before the spot appeared I ve had a funny feeling in the toe itself. Almost like a jolt of light electricity or spasm feeling from mid foot to the tip of the toe.