Re: corner of big toenail turned light brown
Nail fungus us characterized by nail plate thickening, separation, yellowing and apparent thick, wet debris under the nail plate. Pseudomonas bacterial infectionis characterized by nail plate separation, no apparent debris, and the discoloration turns from light yellow to green to brown to black. I suspect Pseudomonas. You will want to see your podiatrist. Do not reapply polish. Keep the area clean and dry - alcohol or peroxide would be better than Listerine. The stain will remain even after the infection is 'dead' and will grow out with the nail plate.