Dual tissue growth between skin and toenail. one month ago, after going for a 3 hour hike, my big toe on my left foot felt very mildly sore and looked slightly swollen around the base of the nail. one week later, a small tissue growth developed. two weeks

Thank : Thank you for your excellent description of your problem. I also love when there is a photo, however the link you provided didn't lead to a photo, but an error. But from your description, i'd say you have an onychia, which is a little infection along the base of the toenail, probably from irritation during the run. The typical scenario is a tiny blister forms from irritation. With continued irritation, the blister breaks and bacteria invade to produce a small, localized infection. It's not serious, and unless there is overt redness, heat and swelling or a pocket of pus, it will probably subside on its own (assuming you're in good health, not a diabetic, no poor circulation, etc.). Keep it covered with a band aid, especially when you run. Warm water soaks will help too. If you keep getting this, you may want to get some roll foam to cover your toe while you run to prevent irritation to the area. In rare occurrences, the nail needs to be removed to allow pus to drain, but this hardly ever is needed. Hope this helps. Happy running!

See podiatrist: Some possibilities may be keratinized tissue, fungus, bacterial colonization, pyogenic granuloma....Without visualization of the lesion harder to give definitive diagnosis. A podiatrist likely can diagnose and offer treatment on seeing the toe.

Sounds like there: is something irritating the area either an infection or an ingrown toenail. see a podiatrist or general surgeon