pea on the toenail
Try Tea Tree Oil (100% pure).
I had an ingrown toe and that cleared it up. but then that is the skin surrounding.
Try soaking it for 30mins twice each day in warm white vinegar. keep it trimmed and cleaned out underneath as best you can. I've also seen some success with diluted (1:3) chlorine bleach.
Over the counter Fungi-Nail works, but you'll have to wear a small gauze compress soaked in it across the top of the nail. Eventually (7-10 days) the nail will soften and you can remove it with surgical scissors (no pain). If you do a good job trimming away the nail and scraping the area, when the nail regrows you have a good chance of it being perfect again.
Tea Tree Oil is the best thing on a nail with fungus.
Takes a few days but it works really well.