Is it a wart? What is it?

I am 26 year old Male. From past 1 and 1 year almost I have this papule kind of thing in my left leg, just below the knee cap. It is roughly 0.4 cm and hasn't changed it's shape or size from the time I have noticed. I also feel it is on the surface only because I can't feel anything if it is squeezed. Whenever I used to scratch it hard will bleed a little then will recover within 2-3 days. If never pains only no sensation on the bump. I have shown this to three dermatologists and all have told this as a wart. I have confirmed with them. They have recommended, if it bothers me then to get it removed. I have picked it and wasn't careful earlier but it has never spread. Now I have used a corn cap which is available in medical shops. After putting it I would feel a bit itchy. I kept for 3 days and get it removed today morning to see that the upper part has peeled of as in picture. There is a reddish area under it is bit sensitive now. Warm water would even hurt a little. What is it?