I had a type of cyst removed from my armpit a long time ago, and until I got it removed, it caused me pain to touch it. Many years later, after showering, I noticed I had a white substance on my other armpit, resembling the shape and color/roughness of a mechanical pencil eraser. Thinking it may be deodorant, I wiped at it, and there was more under that. I started pulling, and I got a string of it about an inch thick, and the width of a mechanical pencil eraser. At the end, I had to tug a little, and the end came out, which looked like it had a piece of skin on it. It felt like putty, and it was sort of flaky. It left a hole the size of the string in my arm, so I sterilized it and covered it up, and it eventually closed. It didn't sting when I used the alcohol and hydrogen peroxide on it though, it felt more like it was being aired out. I never got it checked out, since it healed quickly and well. It seemed to close up and disappear overnight, almost like an over-sized pore. Does anyone have the slightest clue what that could have been? I do have sensitive skin, could that make me prone to different types of cysts?