Listerine Nail Fungus What Type Of Nail Fungus Do I Have?

What type of nail fungus do I have? - listerine nail fungus

In the 27 now, but as long as I can remember I had a kind of fungus on my thumb.
It makes me Cracky mini-yellow in the middle, but no pain or anything.
I have some dermitologist medicine and seems to work, but I'm curious to see what my condition like his, he could not know at the time of the investigation.
Every time I apply medicine or Listerine, little black things on the surface. I've search the net, but Im not sure what they are.
Help please