Holes/ Tunnels in my leg!!!!

Hey, so basically a year ago sometime I had a small red, itchy, it had a black dot in the middle when it eventually pussed out it smelt also very tender to touch. This was on the back of my thigh, I thought this was either a spider bite or infected foilicle so I went to the DR. took anitbotics, used ointments however It stayed like this for atleast a month. Eventually it started to kind of heal. Then around 2 month later I had the same thing except on the front of my thigh. It did exactly the same thing as the one on the back of my thigh. Now I am left with what can only be explained as tiny tunnels, I can put through a pin almost as if im piercing me skin but it doesn't punchure my skin or bleeed nor does it hurt. None of the Doctors here know what it is, It not painfull or nor doe it bother me. I would jsut like to know what are these hole on my left leg??!!! Its bizzare =S